I'm looking for which characteristics I need to get a single access point that should serve 1 medium sized room (about 144 sq. meters) and 8 smaller adjacent rooms (about 28 sq meters), separated by 15cm wide walls made of concrete. I was looking at this and the only thing I gathered was that I needed dual band. The clients would regularly be between 5 and 10, with the possibility of ballowing to 100-120 clients for some hours at any moment of the day. I have a router right now, but its throughput without too much stress (~25 clients) is pitiful given the total speed of the uplink and I need the clients to have reasonable internet speeds.
As characteristics I was thinking of MU-MIMO, 802.11ac standard, but after that, I don't know.
I don't need premium features, like NAS, as its main purpose would be as access point and would be hidden away in the roof of the bigger room.