I had a Ram2500 Shortbed Crew Cab to tow my Elkridge 29BHCK. I had bought a sliding hitch but had never used it, even when backing into my driveway, which at times means an almost 90 degree angle. NEVER NEEDED the SLIDER as my front of my 5th wheel camper boasted an 88 degree turning angle. Well, they were right. I never hit the cab.
Now I am driving a Ram 3500 SRW Crew Cab longbed 4x4. Same hitch just moved it to a new truck. Never need to worry about the cab again.
I will say that it seems a whole lot easier to bcak the 5th wheel with the longer truck. You have more time to correct if you over steer, which after you tow a few times will all but disappear.
Get the truck that fits your needs, as another poste noted. Just make sure that the truck is in the correct weight range for the tow vehicle. Don't cut it too close with the weights though. While a 34/4 ton may tow the amper, it also needs to be able to stop the camper!
Good Luck!