I've got a '96 'Stroke (F-250 x-cab) that I haul an 11.5 ft. camper with, usually while towing my 19' Northwest Jet. I've got 105,000 miles on it and have never had any troubles with it. If you buy an automatic, make sure to use the overdrive off button when hauling.
The warranty is 100,000 on them, so 200k shouldn't be much of a problem, the mech's I know say 300k is easy for them if you take care of them, and get the injectors/vales cleaned aroud every 100k.