I think I'm just gonna get some Pi Zeros + cameras and just roll my own. Probably use the NoIR versions and some cheap IR illuminators. Feed those into Zoneminder.
Bonus points if I can find some old CCTV cameras, gut them, and fit the pi camera to those optics.
I've recently learned that in Linux, you can use emois in filenames. I died a ~~little~~ lot inside when I learned that.