The best combination for your budget would be i5 + GTX1070, but the i5 may struggle a bit in GTA V, especially in city area where population/traffic density is high, causing massive CPU load and potentially some FPS drops throughout the gameplay, not really a problem if you are willing to tune down the settings a bit (those CPU demanding one). This applies to other CPU demanding titles as well.

Intel Core i5 6500 - RM 865
Gigabyte H170-HD3 (D4) - RM 446
Corsair 8GB DDR4 2133MHz Value RAM - RM 171
Palit GTX1070 8GB GDDR5 Super Jetstream - RM 1988
Kingston SSDNow UV400 240GB SSD - RM 487
WD Blue 1TB HDD - RM 209
Superflower Leadex Silver 550W - RM 339
Tecware Alpha - RM 199

Total: RM 4504 (ETech price inclusive of GST)

To keep below 4k, you can:
1. Downgrade to mATX mobo
2. Downgrade to GTX1060 6GB/RX480 8GB (around 60% of the performance of GTX1070)
3. Remove the SSD for now
4. Downgrade the PSU

Remember to x5 instead of x3, you can use x4.5 too but that's normally won't be the final price here 
1. ETech is located in Kepong, you can find their Lelong store here or visit their physical store in Kepong.

2. i5 + GTX1070 yields more frame rates than i7 + GTX1060 in most of the cases (provided CPU is not bottlenecking).

3. GTX1060 outperforms RX480 in DX11 games (most of them now) while RX480 excels in DX12/Vulkan titles (only few currently and will become mainstream in few years time). This little "rule" doesn't apply to all games, some games tend to favor either one of the camps and have one sided performance on it regardless of the graphics API used (DX11/DX12/Vulkan/OpenGL etc). More VRAM is certainly better, but 6GB is enough for 1080p for now, about the age (I assume you are referring to lifespan?), it is very hard to have a chipset failed on you, but artifact is something that is very hard to avoid (depends on your luck).

4. H170 > B150, I am pretty sure that Asus B150 will be more expensive than Gigabyte H170 due to brand name difference, unless you need the specific features of that mobo (or aesthetic purpose), I wouldn't recommend you to go for it.