comments:
In your case, you will largely be focusing mainly on transmit power. Going with WiFi 6 as a older generation will allow you to get a relatively higher end model for less money, and thus more likely to get a WiFi router which will transmit at the FCC limits on the 2.4GHz and 5GHz band. While the client devices will still be stuck with their low transmit powers, WiFi routers and APs have better receiver sensitivity and do not need to make large compromises on the RF front end, thus higher transmit power, especially with walls with a bunch of attenuation, ends up having noticeable improvements in connection reliability and performance. One thing to also consider is if you can go with refurbished items, and add around $10-12 to the budget, you could go for something like the Netgear RS300 https://www.amazon.com/NETGEAR-RS300-100NAR-Nighthawk-RS300-Tri-Band/dp/B0F18YBPWP/ It will transmit at the FCC limits, and has around 4dBi gain antennas on the 5GHz band, and about 6dBi for the 6GHz band, though the 6GHz band has low transmit power due to draconian transmit power restrictions on that band, and with no AFC, there aren't really any options for it to use its full transmit power on the 6GHz band. Outside of that, the only other options are to run multiple APs.
I have a Netgear Nighthawk Wi-Fi 7 Tri-band router. It holds over 100 devices and I have a 2100 square-foot house with no issues anywhere including the backyard and garage and driveway and even out into my street. It is fully customizable, depending on what you wanna do. It has been fantastic. I want to say it was about $250. I also use a separate Netgear Nighthawk modem. I don’t like combo devices at all.Right now there’s one that’s only $131 on a sale. https://a.co/d/09Bmr4S8