I pull a 36 ft fiver with a GVWR of 14,000 pounds. I did not even consider getting an SRW truck because of the pin weight. After much research I bought a 2013 F350 4X4 diesel dually and could not be happier. Everyone here will extoll the virtues of the truck they drive and I'm no different. I love this thing. But I really do think you can't go wrong with any of the big three now. Why did I buy the Ford ? I had a bad experience with my Chevy Duramax and Chevy did not stand behind it so I took my money and went elsewhere. I've also never been one to buy a first year model so that not knocked out the Ram.
I would not buy the Ford 6.0 or 6.4 but the new 6.7 engine definitely appears to be a winner. It effortlessly pulls my trailer and gives me 11.5 to 12.5 mpg.
Strongly suggest that you get the 5th wheel prep kit; I believe all 3 trucks now offer it. I also added Bilsteins and a 40 gallon aux fuel tank/tool box in the bed.
Tim