Michael,
I towed my Viper from Cleveland Tenn. over 850 miles in an enclosed 30' trailer (aprox. 3,000 plus) with my wife's Ford Excursion, 1 Ton truck frame, V-10 Engine. Once the Viper was in the correct place inside the trailer, it did fine. (I had it too far towards the back at first) No real off road possibilities with this other than mild field drive in's for some bird hunting or the like.
I tow a 3,750 LB. stock car (racecar) in a 26' enclosed trailer (aprox. 3,000 lbs) with a Ford F-150 Supercrew. Trailer, car tools, 55 drum of fuel, spare parts, most likley pulling a load of 8,000 lbs plus. No Prob what so ever. This truck currently has 35" Goodyears on it, it rides fine in town, and just got back from deer hunting. Tracking a wounded deer, we drove through a draw planted with sunflowers where stalks were 2 foot taller than the truck. We went off a 24" to 30" vert. drop, without knowing it before it happened, but came right out the other end of the draw. The draw was one mile long end to end. Had to use a buffer for an hour to clean up the scratched paint, but that's what a truck is for. A good in town, good off road, and good intermediate towing truck.
I've owned two F-350 Crew Cab's Diesel's used to tow 24' enclosed trailers with dirt modifieds in them. They had no prob.'s They were the old 7.3 L's.
This past spring I rode in a buddies new 6.0 L Ford F-350 while pulling a 38' Formula boat which is 10,000 lbs by it's self. Couldn't even tell it was behind us.
I had an H2 but never towed with it, My brother towed a 30' trailer to Daytona and Sturgis with 6 bikes and loads of gear in it with his H2. He said it did fine. Trailer aprox. 2,700 to 3,000 lbs. Six big Harley's about 650 to 700 lbs each so about 5,000 lbs..... Four guys gear for two weeks maybe 500 lbs....? Cool ride, however probably not good for a lot of heavy duty hauling. Killer ride like a big fat caddy, killer off road.
I towed a friends Viper in a 1/2 short bed two wheels drive GMC in a 26' encolsed trailer, man that was death waiting to happen! Do not try that at home!
I owned a Freightliner FL-70 Crewcab with a custom tow bed for the back. I towed a trailer that weight was over 8,000 lbs empty. That truck was about $10k more than a loaded Crewcab 1 ton truck. Best tow vehicle I ever owned. It's about 3/4 the size of a big rig.
I can't speack towards any other brands as far as towing goes, however would love to try the big Dodge dually rig.
Good luck with your search.