I'd find me a sprinter based chassis (Itasca Navion or similar)
These drive excellent and have a superb traction control system. You can get bargains on slightly used, they get good mileage (economy and service life)
Key Winnebago / Itasca Sprinter Links - Sprinter-Forum
btw, If you run Bio-d or grease BE SURE to install a heated fuel line and prefilter + a fuel pressure gauge (a very good idea for a diesel any way... $100 gauge can save a $1200 fuel pump). The sprinter has a 'cooling' system on fuel for CR and that is not good for crappy 'soy-based' USA bio-d or grease. Europe uses brassiere feedstock, thus 100% bio-d warranty coverage. USA is 5% BD warranted

. Canada has a good stash of Canola Bio-d, which is much better than US... (National Soybean Council OWNS US Bio-diesel Board governing agency... go figure

) A friend just put an ad on Craigslist for used turkey fryer grease and got a years supply of FREE fuel in 3 days.
I have had terrible luck with the recent Ford diesels, as has our local fire depts.
My cummins stuff never dies, but the dodge chassis has some challenges at a million miles or sooner if newer than '93 (many suspension upgrades needed)
I had a friend with a 1962 Studebaker Diesel (3-53 Detroit) as an RV. Now that thing was impressive AND LOUD (

no sleeping by anyone in campground OR occupants, or within 3 miles while on the open road). I did love to hear those detroit's scream by while living the countryside. No problem understanding the 'doppler-effect' when in physics class
