I just added a wireless one to my truck. Only had to tap into the reverse back up light wires. Two wires spliced, and plugged the monitor into the cig lighter and it worked like a champ. Raining here now or I'd get the make ...wife got it for me as a gift. Said it was the top rated backup camera on amazon.
RTV's don't have the reverse lights but you could plug into any power and ground wire to get the power. Maybe put a switch in to turn it on an off if you don't want it on all the time. I don't tow with the RTV but I know with the truck the camera sure helps.