Q: I am leaning toward ReoLink's 12K cameras

 A lot depends on your lighting. Reolinks, as a rule, are not great at night vision, mainly due to limited config options. I do like their POE TrackMix model though. Two lenses, so you get a zoomed and a wide stream, plus the wide stream helps with tracking in the zoomed view. Better IR night vision than many of their models too.

Do not bother with high MP cameras. Even 4K is often overkill, but 4MP generally looks much better than 3MP due to the sensors involved. Cameras are focused on a targeted range. Adding pixels generally does not let you zoom in much farther, though they might give you a wider view at the target range. That target focus range is not always specified in the specs for fixed-focus models, but it can often be inferred from the DORI numbers. Autofocus can help here, but be aware that a bug or bird might cause the camera to refocus, and it might not focus where you want it to. So, it's best to get it to focus on the target area and lock it there unless it is a tracking model. Never try to cover more area than what your cameras can see without moving.

For choosing models, the same rules always apply. Sort the distances to the target for each camera and decide how much detail you want to see. Match that to the DORI numbers in specs. Then factor in the width of the view angle to cover that target area. Lastly, factor in the lighting needed. Especially for color night vision, you want to compare min lux values and see real video. Many push the specs by reducing the exposures down to the point of ghosting moving objects. Or claim with internal white light on. IR night vision is not as bad. In both cases, you generally want to run without the internal lights. Accent lights for color, or IR floods for IR, are the way to go to keep bugs from visiting your cameras. Oh, and they should support RSTP or, preferably, ONVIF, which most of them do. Ignore the NDAA compliance BS. Do not assume ANY camera is safe, and block them from accessing the internet.

For NVR, go with a PC and Blue Iris or Frigate. Blue Iris has an easier interface and has an extendable AI, but is Windows-only and $100 for up to 128 cameras. Frigate is free and runs on Linux, but can be challenging to set up for non-IT types. Both work with cameras that support RSTP or ONVIF.