Where to start? I looked into aluminum trailers (2 months ago) and surprisingly, they only save about 400# and are triple the cost.
You don't want anything older than 1999 in a Ford Chassis. That's when they went to the wide track front suspension. Much better ride. Between 99 & 04, the GM driveline was a higher HP/torque. But in 2005, Ford upped the Triton to be on par/ a little better than the Workhorse. Basically, either one works.
Mine is a 99 Ford, 32 ft Class A, no slides. Our recent trip to Moab was a great comparison. Tab's 35 ft'r has the higher hp but is also heavier with 2 slides. On the grades it appeared that they were about equal depending on who hit it at the right speed and gear. There were times I felt he did better against the wind.
I have pulled my 20 ft enclosed trailer since 2007. My jeep weighs 4600#, trailer title is 3400# and with all the shelves, tool boxes, work bench/vise, etc., I am pushing the envelope. Another way to compare, my CGVW is 26,000#. While at Bundy Hill last year I had it weighed, tanks were mid level and I didn't have my spare tire carrier rack installed. I was 25,850#.
In other words, MAXED out. I have pulled this combo from Canada down to TN. I came to the conclusion that I was not comfortable pulling the enclosed to Utah this spring so I bought a new flatbed with a wt of 1460#. I figure that between the title wt difference of #2000 and all the crap I really didn't need, that I saved 3000#. IT WAS WELL WORTH IT. I was down to 24 mph, running 3800-4000 rpm for MILES at a time on the big passes.
Looking back, I would NOT pull my enclosed out west with my current MH. I am also convinced that Tab would not do a whole lot better pulling an enclosed.
RE rebuilding my trans; I started pissing tranny fluid some time last summer. It would only happen while at super slow speeds. I actually found that it was happening while trying to maneuver in tight places while using reverse. A discussion with Tranny Tom concluded that the Ford trans doesn't like high loads in reverse. I considered a PM rebuild last fall but it didn't happen. This was another reason I opted for the flatbed prior to Moab. I had no trans problems on the trip other than a few drips that amounted to about a pint of oil each way. But when I got home after dark, the jockeying around to back into my driveway resulted in pissing a solid quart of oil onto my driveway.
So, I decided to pull it. Tom found that the torque limiter had started to "balloon" and there were signs of heat on the bands and clutches. I am currently in the process of installing an additional trans cooler with dedicated electric fan to assist in cooling at slow speeds.
Frame. Yes, you will need to beef up your trailer hitch and possibly the frame depending on what you buy.
Deisel. Lots of cash. Don't waste your money on the lower hp/torque units.
I had a 24 ft Class C. I would not go back to it for a couple reasons. The visibility in a Class A is worth it alone. The van style cockpit is much tighter, especially footroom. Ours would not allow the passenger seat to go all the way back due to cabinet interference.
So, what to recommend KNOWING that you will be hauling an enclosed?
Class A as short as possible. 32-35 ft is more than enough.
No slides to reduce weight and offset your CGVW.
2000 or newer Workhorse.
2005 or newer Triton.