Ship, I am planning on buying the same camper. Great choice!
I have a GMC 2500HD with the 6.5 bed. The dealer was definitive I do not need a slider hitch. I'm likely to put in a B&W turnover ball and either a B&W Companion or the Andersen Ultimate Connection that goes on the turnover ball. Either would be an excellent choice.
I have a Roll-n-lock tonneau on mine. Spendy, but worth it. It rolls into a storage area at the front of the bed.
I'm eager to hear how you like the new camper when you get it. Congrats on it and the new truck.