Wow... wires all over that sucker. Looked like he had some other non-camera wires at the bottom on one part. My wife would kill me if I had any wires showing on the outside of the house like that. When I installed my cameras I made sure I had zero wires showing on the outside of the house. Only wires I had showing were the settings cable looped out for a bit as I adjusted things. Once I was happy with it all the wires went stealth.
What's wrong with multiple DVRs of the same brand? As long as the manuf has a program that allows multiple DVRs in one app. Most of them that I looked at do. Break them into zones and then it also removes the single point of failure issue as well.