I looked into this before I ordered my truck but decided to go without or after market since I wanted to be able to have it on at my discretion, especially while driving down the interstate.
If I had gone with the factory radio, I decided I would go with a factory replacement camera and build a custom mount to hold the camera on the back of the camper. Then it would just be another connection to make after loading the camper. The truck would never know.
I think the camera and harness was very reasonable at $200 or so. Available on ebay. Believe
this one should work but not sure.