I tow a 25' Coachman that pretty close to what you are towing. With my Ram 1500 Ecodiesel it handles it with ease and are perfectly suited for trailers of this size and weight. And would recommend looking and test driving one before pulling the trigger on an F150.
I know there are still a lot of misconceptions out there on diesels these days. If I pulled the diesel badges off my truck you would never know it was one. Diesels these days are very quite and do not have diesel exhaust smell of the old days.
For reference last year I averaged 14 mpg on a 4K mile trip towing the camper.
As far as configuration. If you never plan on towing in snow or off road a 2wd should do just fine.