can you tell more on your unifi speed package and current router
but generally if your area is large. It is recommended to work with mesh setup such tplink deco mesh or asus aimesh just as forummer suggested.

go for mesh and use ethernet backhaul. even though more expensive at first, in long run can support for another 5 years down the road

1 mesh on paper numbers can cover 1k-2k sqft through signal but speed wise wont be close to LAN ethernet port speed.

so i assume your bungalow is around 3k-4k sqft.

you need a 3 pack mesh wifi 6 to cover the 2 floors. for last mile weak wifi signal area...you can just reuse old routers as repeater or set ap mode but need more cat5e cables.

do you have existing ethernet wire ?? if your house got internal or wall ethernet , I suggest find 2nd hand routers with ax1500 rating above.

The main router get a good reliable one like tp-link/asus/or tenda.

Since 11.11 is  coming soon, I'm sure  you can find a good deal.

After much reading and fact finding, TPlink AX75, but 500+, tenda tx9 also around 300+.

In term of coverage, I had heard of the legendary tenda ac18/23 but forummer say latest one range not as large as its siblings
in the selection i think at least need to buy two same unit and mesh them up which is the best way to ensure compatibility
for a bungalow. Too bad there are not much review online for the unit u have in mind, but there is some discussion on lowyat which i link up for you to read

If only from your selection, I would choose xiaomi ax3200 x2 for probability of flashing openwrt in the future.(Note do not do this if you do not know what u are doing flashing incorrectly may brick the device)
but if u can setup ethernet link between the mesh buying dlink ax3000 the unifi branded router from used market would be cheapest for 2 unit from used market place.

Anything is better than China domestic market routers as their 5GHz signal is very weak due to China regulation

They have strict limit on 5GHz transmit power due to their high population density at major cities, if everyone blasting their WiFi on 1000mW it will end up with a really noisy and unusable network

Their limit is 250mW and most of our routers here support close to 1000mW

And no, whatever WRT custom firmware cannot bypass that

None of those I will consider tbh.

Get tp link ax55, easymesh ready, can buy another one (same model) if you want

Consider the XE75 maybe? If you want guaranteed coverage and best signal possible, also 6E as well which if you have semi new devices it'll be faster as well

Or X50 which is gonna be a bit cheaper and still offer good coverage and performance

Just gotta make sure you use a ethernet backhaul to the nodes

Since your property still on building stage, ask your architect to include Ethernet cable in the M&E plan

Depending on how big is your bungalow, at least one unit per floor. If it is bigger, at least 2 units of router every floor front and back.

Model will depends on your budget and what speed you plan to subscribe.

Deco mesh can be router as default, ap mode optional

If you already want to buy at least two at one go, deco series is better option

As I’ve never used Decos myself, I can’t say for certain but if TP-Links Malaysia guide is anything to go by, your ONU can be directly connected to the Deco, and all the services like PPPoE, DHCP etc is handled at your main unit

And just subsequently pair each Deco as sub units to extend your WiFi coverage. You can pair using WiFi but it’s best to just go wired backhaul

Mercusys is "junior" sub brand from tp link parent company
Sure due to being on the budget side, besides of design differences, software may be more simplified in terms of features and support limited

which chipset doesn't matter actually.

what's most important is that under a long term usage, will the router heat up badly, the design of the router ventilation.

How stable and effectively it can run without restarting occasionally is the most important part.

I've read on TP link forums , some users are complaining their AX model still run into restarts, or lagging. Could be firmware or hardware issues, so in the end no solve all method, just trial and run/

But suggestion is to get ethernet backhaul if you want full signal + speed coverage.

Buying a MR90x might be able to cover whole floor, but I doubt you'll get full Wifi signal coverage on the 2nd floor, and even if you get, your speed is going to suffer tremendously.

So best option to get those ethernet conduit and power plug socket built into the walls and placed strategically installed at mid point of the floor to make sure you can place either mesh/router at the right places.

This way you won't have to break your head over which location to put your router even in the future. Because at the right spot with necessary existing cabling, you are future proofed for the next 5 years I dare say.

Mercusys is budget brand and there will be things cut to reach a lower price

TP-Link would be more fully featured

TS, consider also Asus routers, AsusWRT is quite powerful, can also reuse as mesh

For me the only advantage of mr90x over others similar priced is mtk platform for openWRT support, you can check out how complex it can be

mr70 is the only router so far i search for ax1800 rated that is below 200 and has one of the latest baked into it like BSS,TWT and ODFMA. whether does it really works or help, is yet to be fully proven.

also , i checked on mercusys my website...only mr70x latest firmware has easymesh enabled on it, mr80/90x no easy mesh available yet.

11.11.. is on sale for 148 for mr70x

My first Asus router was the N56U i think. And i bought it 2nd hand too.. Lol. That time it was like RM100, way better than the default TM router, useless like anything. My mom keep nagging me saying the wifi so slow. lol. Ended up with that router for i think  2 years before it KO-ed. Bought another 2nd hand N56U. used for a year and it seems like it was gonna KO, so i bought AC86u that time, bought wrong time, because right after that price dropped drastically.. lol. Bought at RM800, i think a month later was like RM600.. I bought same time with my AX56U, just launched that time, RM600 AX56U. lols. Oh wells. haha. What's done is done. But I am very satisfied with Asus routers. The UI is very easy to navigate. Overall I would recommend Asus. xD

Try Mikrotik.  Free Software upgrade untill it breakdown. After 10years you can set up as AP or LTE. Mikrotik stuff hardly breakdown.

Yes Mikrotik stuff is powerful and reliable

The problem is it is quite advanced, being a SOHO/Business product

Not sure if TS is willing to put in the effort to set that up compared to just a more plug and play solution of placing down a few consumer routers