How much time is your truck going to be hauling your trailer? If you are going to be on the road full time, then a one ton diesel makes sense in terms of capability and fuel cost. If you are going to be on the road one or two months a year with the truck being used for short trips around town the rest of the time then a big diesel will never pay for itself and short start and stop trips will actually be bad for it. An alternative might be an F150 supercab with an Ecoboost V6. It will haul more than twice your payload requirements and be far more versatile when you are not hauling a trailer.