One thing to add that
@wittaj may not have mentioned here that he's mentioned elsewhere is that he likes things closer. The more experience I get with this, it's some of the best advice on this forum. What I've found is that if I think I need a 2.8mm camera, I'm much happier with a 6mm camera. What that means for me is that most of my cameras are varifocal. The benefit is that you can move them and zoom into areas, which you can't do with a fixed lens camera.
Also, one of the recommendations on this site is to get a varifocal camera and place it temporarily where you plan to mount a camera and see the results at different focal lengths. That is great advice! But, be sure that you can identify in the areas you are covering before you buy a fixed camera.
I'm not sure if either of the above were mentioned, we're fixing dinner and I don't have time to read through...But, wanted to post those two points.