I also investigated backup cameras. because of others' experiences in poor reception, and irritation with cheap wiring, I bought $1,000 worth of commercial grade cameras. What did I get that $300 didn't?
* heavy duty wiring and enough of it.
* a bright monitor that will switch between truck and trailer camera
* heavy duty waterproof connections and a spiral cable (looks like a real trucker cable
between trailer and truck.
* good instructions
* Plenty of signal
* auto heaters in the cameras to prevent fogging (betcha didn't know that could happen)
* ir for night vision (helpful when backing at night)
* pressure-wash proof
I know I paid a lot for it, but it works, and every time. For a year now and
over 10,000 miles.
What I didn't like:
*The first cable that came with it broke. They sent a new one.
* Though you can control contrast and brightness, it is not automatic. If cloudy, you need to adjust. I believe the new models have a day/night mode.
* Fisheye in the back of the trailer could be a bit narrower.
* rain gets on camera occasionally and blurs. I use rain-ex to minimize this. However, mud needs to be wiped off.