Look at this Pyle, Amazon has it:
CameraIt makes backing up that long truck a lot easier since it has a huge dead space behind the truck that is invisible to the driver. This camera also has a hitch up mode for TT that has guide lines just for that. It guides you right into the trailer ball. I was surprised to see how easy it made the process. It's cheap too.
That backup beeper has so many false alarms that you tend to ignore it after awhile. A good rainstorm that leaves wet dirt on one of the lenses will drive it crazy for example.