As you mentioned payload is your biggest issue and is reduced anytime anything is added besides a 150lb driver and tank of gas, you may only have 1000lbs to work with. Our 32' TT is well over 1K of tongue weight with batteries and full propane tanks, you will need a high quality WD/SC hitch to control these long rigs particularly at interstate speeds and under windy conditions. There are forum members that tow with an Expy, they could provide specifics on their towing combination and what they have found as limiting factors. Good luck and enjoy your new TT.
