Looking for expert tow vehicle advice/opinions

I think you need to have a very good idea about which 5th wheel you'd like to buy. I don't think you can make an economically intelligent decision on the truck until you've made the decision regarding the 5th wheel. As others have said, whether or not you'll need a 3500 DRW will depend on which 5th wheel you purchase. That said, if money is no object, you can always go big on the truck with the mindset that whatever fiver you get the truck will be able to handle.