Sorry, I'm probably violating at least one of your rules, but what minivan has a 5,000 lb. tow rating? We may be looking for a replacement for our Odyssey in the coming years and I've yet to see any minivan with more than a 3,500 lb. tow limit, and even that is usually with only a single occupant in the van.
Why don't you just look for DP with a 10,000+ lb. tow rating? There seems to be quite a few of them around. In fact, I just checked on the 2000 Newmar Brochure and that floorplan on the Spartan Chassis has a GCWR of 37,400 and a GVWR of 27,400, so it should be able to handle 10,000 lbs.
So, I suspect if you do research (maybe you already did) on the differences between the Spartan and Freightliner chassis of that era, you might have an answer.
Well, whatever you decide, good luck in your search and decision.
~Rick
