I think it depends on what you want out of a camera system. If you only plan to use it for reversing purposes, then it will only be used a couple times during a trip, and the system doesn't have to be as rugged as a full-time monitoring system. However if you want a full-time rear-view monitoring system I would suggest going with something designed and well proven for the RV/Trailering community.
Personally I use an ASA/Jensen Voyager RV monitoring system. Uses a permanently mounted wireless rear-view camera, and a 7" color video/audio display that's mounted in the tow vehicle. Monitors the rear-view full-time when in use. I bought a second camera and mounted it on another trailer I tow as well. Really like the system but it's not cheap.
http://www.jensenrvdirect.com/produc...a-systems.html