I would echo what Farmerjon said. We recently traded our '13 GMC 2500HD for a '12 F-350 DRW (actually had 3,000 less miles on it than our GMC). The reason we did this is because, with a SRW truck - whether 2500/250 or 3500/350, you run the risk of reaching the max load limit on the rear tires of the truck very quickly with a single rear wheel and a fifth wheel. Look at the GVWR (not the published dry weights or pin weights) of the wheels you are considering and take 23% of that GVWR for an estimated loaded pin weight. Our loaded "mid-profile" fifth wheel (13,990 GVWR) rolls across the scales with 3,100 lbs on the pin. We are MUCH more comfortable with the DRW truck. As for brand, see if you can find a truck with the Cummins turbo-diesel, the Allison 1000 transmission, a GM chassis and front end (steering), and the Ford interior and body. In other words, find a DRW 1-ton truck you like and get it.
Rob