Our fifth wheel came pre-wired with a mount for the Furrion rear cameras and we installed one. They have two versions: one that is intended for a backup camera only and one that is higher resolution and sample rate for full-time rear monitoring (we have the latter). My wife is still behind me with a two-way radio when backing into tight spots, but I find the camera handy for judging clearance to pull back over after passing and backing into parking slots at truck stops. Our total length is about 50' hitched up and the wireless camera/monitor works well from the back of the 36' trailer to the dash of a long wheel base, long bed, crew cab truck.
Rob