I use 8MP Hikvision POE cameras with BlueIris to integrate with HA. There is a good writeup around here, also playing with Tensorflow person recognition. If you can snake a CAT5 wire definitely recommend wired over wireless just due to the battery replacement hassle. Also if you have a lot of cameras on Wifi it can overload it, I was recently at a friends house who has almost unusable Wifi after his camera install. Each 8MP camera is pulling about 4-5Mbps. The crux in this setup is Blueiris CPU usage. It is good to have a dedicated NUC or other box with onboard Intel graphics processing if you plan to use multiple cameras.
There has been a lot of concern about Chinese made goods and spying, which is not unfounded so I always take a network capture of traffic to test them out. The Hikvision cameras do not ‘phone home’ to China out of the box like some of the knockoff Chinese cameras and other devicesI have tried.
You should also think about MP and lens type. You can find plenty of demo videos on youtube for various brands that should help you decide the quality of video and FOV that meets your requirements.
When buying cameras I always get ones with ONVIF support, I prefer PoE. But if I get a good deal and they aren’t PoE. You can make them PoE with an Adapter like this:
Another vote for Blue Iris here with the Reolink POE cameras, POE is the way to go if it’s possible. I’ve got my Blue iris running on a Dell Optiplex 990 with 8 x Cameras including 1 x 5MP and the rest are 4MP. 1 x Unifi the rest are Reolink, I’ve had them for about 3 years, still going good.
The Dell Optiplex (or similar models) are cheap as second hand, I got mine for $180AU and added a 3TB HD and a 120GB SSD and 8GB RAM and it could probably take another 8 cameras and work ok, only it would’t store the footage for that long with 16 cameras.
You could probably run your Home Assistant on the same computer too, on a VM that was my plan, I setup the VM and home assistant on it, only I haven’t gotten around to transfering from my RPI to the VM yet.