Sorry got nothing to contribute on that system, but since you know your electronics any reason you went wired vs wireless? I've been thinking about a wireless system.
Saw this one from your link https://www.ebay.com/itm/Lorex-4-Cam....c100009.m1982
For me 1080 is fine as 4k seems a bit overkill if just to collect evidence.....save the 4k for the bedroom camera
P.S. You really building this house yourself or just meant paid to get it built....just curious as I picture you in your carpenter belt.