I wouldn't carry anything in particular aside from the basics (which you seem to have pretty well covered). Frankly, I suspect you'll have more trouble with the house systems than with the Ford chassis; it's pretty rugged, and if it does have problems service is not too hard to find, nor are parts rare and unavailable.
A year and a half ago I took a cross-continent trip (Vermont to Alaska and back) in my '98 Ford E-SuperDuty based Coachmen--the E-SuperDuty was renamed to the E450 after a couple years--and the only chassis problems I had were "permanently lubricated" ball joints that ceased to be lubricated due to the rubber booties breaking down and wearing out, and a tire that failed. Carrying a spare set of ball joints doesn't seem at all logical, and I could put my spare on to get to a tire shop and replace all the tires as they were getting pretty well worn by that point at the end of the trip anyhow.
I'd just make sure it's up on regular maintenance and enjoy the trip.
