"Curb Weight 6,480 – 6550 (I see different amounts depending on what site I go to)"
I think the truck you are considering will likely be at least 7K curb wt. Still not a problem, the truck will be capable.
The number most important for towing a FW is the RAWR of 6,340, which will work for the trailer described.
You don't need a long bed, or a sliding hitch, as the newer FWs are designed to tow with a standard bed truck. Get the B&W hitch to fit the Ford OEM pucks. It is adjustable ahead/back, and a great hitch. Hitch weighs just over 150 lbs, and is a very user friendly hitch.
I agree, if at some point, you want a larger FW, weighing 14-16K, then a 350 would be best.
Jerry
