Weigh your truck as if loaded for camping. Subtract the scale weight from your 7100 payload. The difference will be how much hitch weight you can safely accomodate. Keep in mind that the posted tongue weights posted on Rv manufacturer literature is unloaded weight. Figure tongue weight will equal 10 to 13 percent of the gvwr of what ever trailer you look at. Ignore the dry weight numbers.
My guess is that you should stick with a trailer loaded no more than 6000 lbs and no longer than 24. Anything greater may bring an unpleasant Towing experience. Your 3:42 axle may also limit what the powertrain can muscle on hilly terrain. Don't let rv salesman tell you "you can pull that no problem". Do your own research.
Good luck and have fun shopping.
