I've been watching this thread, and as of yet, hadn't replied because I wasn't sure how I could do it without spending a fortune. But it just occurred to me that most of these electronics use AC adapters.
So I went and found this system, which specifies the power input as 12v/2a. My theory is that all I'd have to do is cut off the 120v plug and wire it to the battery bank, correct?
All I really want is 4 cameras, two for each engine to monitor the belts on the front, and the shafts on the back. And this system has an HDMI output for wired viewing at the helm, and then I could also connect it to our on board hotspot for away from home monitoring.