The best devices we used is Dahua IPC-HFW4431R-Z, it balanced price and quality very well. You can easily purchase it on Amazon.
With 2.8mm setup, the Face Recognition distance is 1-3m, if zoom the lens to 12mm, the Face Recognition distance will be 4-8m.
We ported the system/software into RK3399 Set Top Box. Since it's less expensive.
There's heat problem with this setup due to hardware design(heat sink is located on wrong side), you need open box and setup a fans to keep it running overnight/weeks.
Just for example, RK3399 STB
Our image only support 4GB 32GB for now.
Most of them works. The Dahua camere is sold without power adapter so POE injector is needed.