Lot's of question ! I will try to answer a few.
Most (all) Class C motorhomes are built on an E-Series chassis. This is very different than any F-Series chassis. The biggest difference is in the cab. There are significant differences in the chassis.
Depending on when the chassis was manufactured will depend on what engine and transmission you will. I think the only choice is a 7.3L gasoline engine with 10 speed transmission.
Huge difference between a 32' Class C and a 32' TT. You need to look for yourshelf.