I just received this e-mail and have to say I may be more confused than ever!
Remember the GVWR is based on several factors but most of all the suspension of the truck. The addition of the air bags added 1600# to my adjusted GVWR on the Dodge. I was able to pull my 40 foot unit with the Dodge without any problems and it is 14,000# dry so I assume it was in the range of 16,500 to 17,000 when loaded and I always travel with full tanks of water. I think you will be fine with a good hitch, air bags and upgrading to a tow package. I would try it before I spent the money on a new truck. I have a friend that pulls a unit like mine with a 2012 Ford ¾ longbed and he added the air bags to bring the truck up to the desired GVWR.