Cameras with good quality

Hello! I have one camera on ffmpeg platform. I had to use really low quality of picture to have real time image. As I see, raspi does not like that. Usually processor works on 4-8%, while I am watching camera - 40-60%. And it is happening with really bad quallity with only one camera. For future I want to get more cameras with special DVR (I hope it is right name) which will record the video. Can I integrate it with Home assistant(I want all processing to be on DVR, and live picture to be in HA UI)? And is it possible to do that with so fi cameras? Or I will need Ethernet anyways?

I use Xeoma for that. Can be installed on a Rpi but now I have it on my home automation nuc in a docker container. HA has a component to show the cameras live.