OP
In a nutshell without all the banter, a gas will be just fine but a diesel will pull better. It's nothing more than getting either one configured in a manner and equipped to handle your 5th wheel. If only towing 2000mi or so a year, then the upfront cost and added maintenance probably isn't worth it. Unless you just really want a diesel and don't mind the extra cash up front (pretty substantial) and added cost of ownership (not a big deal) I believe you will be fine with either one. And as someone else pointed out, if you plan to trade at roughly 80,000mi, then the diesel seems kinda pointless to me considering your needs and plans.
