Location SG, are you buying from SG? If yes then I cannot help you with the pricing (and most likely the build as well since product range is different).

GTX1070 non reference is not released widely here yet so we have to wait for few more days/weeks before we can find out which one comes with highest OC capability and most importantly its price.

Currently the fastest GTX1070 is Asus Strix with boost clock up to 1860MHz, Zotac AMP Extreme and EVGA FTW Gaming and Gigabyte G1 Gaming should be the closest competitors (unannounced speed).

Intel Core i7 6700 - RM 1305
Gigabyte H170M-D3H (D4) - RM 424
Corsair 16GB (8GB x 2) DDR4 2133MHz Value RAM - RM 262
GTX1070 Non-FE - RM 2300 (Estimated)
Seasonic M12II EVO 620W - RM 363
Corsair Carbide 88R - RM 226

Total: RM 4880 (ETech price inclusive of GST)

Not much QHD monitor in Malaysia to choose, not sure if the situation is the same in SG or not.

1. Dell U2515H - RM 1439
2. Dell U2715H - RM 2265
3. Dell S2716DG GSync TN 144Hz - RM 2669
4. Acer Predator GSync IPS 165Hz - RM 3189

Intel Core i7 6700 - RM 1305
Gigabyte H170M-D3H (D4) - RM 424
Corsair 16GB (8GB x 2) DDR4 2133MHz Value RAM - RM 262
GTX1070 Non-FE - RM 2300 (Estimated)
Seasonic M12II EVO 620W - RM 363
Corsair Carbide 88R - RM 226

Total: RM 4880 (ETech price inclusive of GST)

Not much QHD monitor in Malaysia to choose, not sure if the situation is the same in SG or not.

1. Dell U2515H - RM 1439
2. Dell U2715H - RM 2265
3. Dell S2716DG GSync TN 144Hz - RM 2669
4. Acer Predator GSync IPS 165Hz - RM 3189

Intel Core i7 6700 - RM 1305
Gigabyte H170M-D3H (D4) - RM 424
Corsair 16GB (8GB x 2) DDR4 2133MHz Value RAM - RM 262
GTX1070 Non-FE - RM 2300 (Estimated)
Seasonic M12II EVO 620W - RM 363
Corsair Carbide 88R - RM 226

Total: RM 4880 (ETech price inclusive of GST)

Not much QHD monitor in Malaysia to choose, not sure if the situation is the same in SG or not.

1. Dell U2515H - RM 1439
2. Dell U2715H - RM 2265
3. Dell S2716DG GSync TN 144Hz - RM 2669
4. Acer Predator GSync IPS 165Hz - RM 3189

Incorrect. Gigabyte GTX1070 G1 Gaming only requires one 8 pin PCIe power connector which means the max draw from the PSU is 225W (150W from 8/6+2 pin PCIe power connector and 75W from PCIe slot) when running this card, 620W is more than enough for any GTX1070/1080 setup even if you are running an OC setup (K CPU).

There are many different types of mATX cases out there and their extra 5cm height and 2cm width on mATX case claim is invalid, mATX can be as small as mITX case like Silverstone SG01/SG02 etc.

You can look for Corsair Carbide Air 240, Xigmatek Aquila, Fractal Design Node 804 as the alternative if 88R is nowhere to be found, I suggest you to go other shop instead, the shop you went seems unprofessional, most likely another typical shop trying to trick their customer to get what they have/clear their stock 

BTW we have a limited choice for mATX case in our local market because usually mATX build is for budget rig, why I said so is because mATX mobo is significantly cheaper than ATX/ITX, those who are looking for portability or have limited amount of space will usually go for ITX build instead.

Totally wrong.

Most people don't even know what they're talking about when it comes to power draw of a system.

Read carefully http://www.gigabyte.com/products/product-p...spx?pid=5916#sp

Recommended PSU : 500W

RECOMMENDED and REQUIRED are 2 totally different words.

And do you know how much a system with GTX 1070 draws?

Try take a guess on how much my system with Core i7-5960X @ 4.5Ghz (50% overclock) with GTX 1070 running Furmark (draws more power than gaming) draws on peak.

The answer.......... 268W..... and that's just peak, and that's just wall draw.

Actual system draw is less than 250W. The graphics card is estimated to draw only about 134W.

If you plan to get another card for SLI/CF in the future, then you need to get a SLI/CF ready mATX mobo too and the option is very limited in Malaysia, we only got 1 model which is the expensive Asus Maximus VIII Gene, I am not sure if the situation is same in SG or not, if yes then prepare to burn your wallet for it 

Phanteks P400s (a.k.a Eclipse) is a standard ATX mid tower, if the size is ok for you then go ahead 

Both P400s and FD Node 804 support liquid cooler (radiator mounting point available), they aren't really made or aimed for liquid cooling build, almost all cases have at least 1 radiator mounting point (120mm) now, even the lower end one like Tecware Alpha, it has become a trend to have at least 1 even though it might not be useful for all users out there.

I am not familiar with the shop in SG, sorry cannot help you on this 

Palit 10 series card is short compared to other brand with triple fan but it is very "fat" because it takes 2.5 slot instead of 2 slot, it can fit in 400C.

Depends on games, average FPS on 1440p is > 60 FPS according to most of the benchmarks posted online but min FPS is not always guaranteed will be 60 as it ties to many factors, games optimization, things/stuffs to be processed during a certain scene etc. Player is expected to experience some input lags from non-GSync/FreeSync monitor when VSync is turned on, those lags/screen tearing are hard to avoid with normal 60Hz monitor. FPS drop is acceptable to me if it is just for 1 or 2 seconds as long as I am not playing the whole games at 40 FPS, different people have different acceptance level though, lower down the graphics settings if you want stable 60 FPS.

Liquid cooler isn't easy to clean as well, the dust trapped on the fins of the radiator can be PITA to clean, you need to get a compressed air can to eliminate them to reduce the risk of damaging the fins when you do the cleaning, air cooler is easier to clean in my opinion but their size is very big which doesn't help in aesthetic purpose 

The mobo model you listed doesn't exist. Nobody can guarantee it can last for 10 years, maybe you need to ask yourself, can I stick with Skylake for 10 years? Core 2 Duo is a 10 years old CPU as of this year and it can barely handle any latest GPU (except low end one) for latest games, I would say 5 years is the max limit for me.

WiFi can be added separately, either by USB or PCIe. Same goes to USB Type C, if you want native Type C support, you need to get something like Gigabyte H170-D3HP.

520W is fine and it comes with 6/8 pin PCIe power cable.

You can refer here under "Cables" tab (PCIe).

As for the mouse and keyboard, normal non-gaming mouse and membrane keyboard will do?

2133MHz is the base speed of DDR4 RAM, so nope. As mentioned earlier, only Z170 mobo can utilize RAM speed of > 2133MHz.
Different people have different preferences especially when it comes to mouse and keyboard so the recommendations below are solely based on my preferences and liking, you can read more reviews online to determine the best mouse/keyboard that suits your style.

There are 2 types of mainstream keyboards in the local market, membrane and mechanical.

Since no budget stated, I assume you don't have a limit on these 2 items. I am eyeing on Corsair Vengeance M65 RGB and Logitech G700s for mouse and Corsair K70/Strafe RGB MX Blue (mechanical) for keyboard. Personally I think it is not worth to spend RM 300+ for a membrane keyboard, so try to avoid those "high-end" membrane gaming keyboard, it is still carrying membrane typing feel no matter how "high-end" or expensive it is to me, entry level of mechanical keyboard beats them easily.

MX Silent and Red switches are the switches that you need to look for if you are going for mechanical keyboard since you prefer a silent keyboard (Razer have their own switches, same goes to CM and some other vendors who don't have agreement to use Cherry MX Switches on their keyboard lineup), MX Blue is noisy while MX Brown is in between MX Blue and MX Red, there is also a new switch from Cherry which is currently under Corsair exclusive, MX Speed, specially made for gamers (Dota 2, CS:GO etc.)

No metal in it? Not sure what you mean 

If the last 2 pin is detachable from the main 6 pin then yes, it is the correct PCIe power cable that you are looking for, that's why it is advertised as 6/8 pin PCIe power cable, some GPU use 6 pin only, like most of the GTX1070 and GTX1080, some use 8 pin, so users are able to detach or attach the last 2 pin according to their needs.

Ducky Tenkeyless is around RM 300+.