[travelin texans]

This has been said A LOT on here!
Dry rv weights, tongue/hitch/trailer, mean ABSOLUTELY nothing to the rv buyer, that's what they weighed coming off the assembly line & will NEVER EVER weigh that little again. Same as the max tow weight of your tv, you'll almost always exceed the max payload long before you'll tow max weight. Unfortunately the rv industry has deceived a lot of buyers with their "half ton towable" misadvertising & neither rv nor truck dealers know or care about what you can/can't tow, selling is their goal.
Use the GVW of the rv times 20% to get a VERY reasonable hitch weiht for a 5th wheel plus the weight of the hitch, people, & anything in or added to your truck & compare that to the payload of your tv then you'll have honest numbers to work with.
Unfortunately I'd have to agree with others here, too much rv & not enough truck.
If by chance you go with this rv & upgrade trucks, go with the 3500 not the 2500, not much difference in the ride & very little difference in price.