I drive a 2013 VW Touareg TDI SUV with a 3 liter turbodiesel motor. Towing capacity of the CHASSIS is rated at 7700 pounds and 770 #'s tongue weight. That is what the chassis is rated for. I can tell you that at 3800 #'s dry weight with my 21 foot Palomino Gazelle, once loaded up with another 500 or 600 pounds of goodies with just Me traveling solo, that trailer with much more than that would be crazy, out here in the mountains west of the Rockies. It drives fine 500 miles a day at 55 mph, and I know, I've done it 3x from Los Angeles to West Yellowstone, solo, in 2 days, each way, and a trip to Breckenridge, CO also.
Going much bigger, get a long wheelbase truck, preferably a 3/4 ton model, at a minimum, with 5 of you and 25 feet or more of trailer. You need that long wheelbase with that length of trailer or more.