I like doing my homework. After studying some of the wiring diagrams, I think I have this thing figured out. I will give the secret sauce away after a test run, but I am pretty confident, (or I would have tried it before even saying this). My plan would allow for as many cameras as you want...
I am thinking the same exact thing. Splice a front camera into the rca connector (or 2 other cables that act as the rca coaxial) and connect the power to the upfitter switch. If reverse power kicks on, rear camera is active, and if in drive and turn the upfitter on and the front camera actives...