You need to do your own wireless site survey since every environment is different. Variables that impact wireless range and speed are building materials, active user density, RF – electromagnetic interference or CCI – Co-channel interference
A repeater or an extender degrades your bandwidth since it has to use it to communicate with the main wireless source and the clients. They do extend the range but they also bounce back all the router’s traffic, creating congestion and slowing the network. I recommend access points instead.
The wifi capability built in routers is inferior to access points. 2-in-1 of any product is generally inferior. What you can do is buy a router without wifi capability and compliment it with an access point which will be your main source for wifi. I did that but with an enterprise grade router and access point. I found consumer grade to be insufficient.
In the newest models, the average sq ft coverage of a single enterprise access point using ac standard at 5ghz is around 4,000–5,000 sq ft.
As a frame of reference for you, I live in a 2-family house on a property of around 4 acres – 174,000 sq ft. There is an abundance of CCI in the area. Building material is concrete and steel with around 60 active clients streaming high quality videos. I’m using a bunch of Ruckus ZoneFlex R710 access points which have the latest ac wave 2 wifi standard. A single R710 covers around 5,000 sq ft for me.
I have two internet providers for backup incase one goes down, so I needed a dual wan, loading balancing router. I use this one Peplink Balance One Core Load Balancing Router
If this is too pricey for you and you only have one internet provider, then you can try the following cheaper alternatives which are still considered enterprise grade. Single wan router – Ubiquiti Edgerouter PoE and one of these access points Ubiquiti Networks UAP-AC-PRO. That is the highest wifi model and from the same company these are the lower models, Ubiquiti UAP-AC-LR and the lowest UAP-AC-LITE
If more than one access point is used, you have to make sure they’re not sharing the same channels and the best place to position them is mounting it on the ceiling.