Bill's advice is good, as usual.
The only advantage of a rotisserie (unless you can borrow one for free) is that the cab would be higher off the ground, and maybe a little easier to work on. I use a few hunks of 6x6 post-lumber (about 16"-36" long) to raise the cab off the floor.
How much metal work do you have to do on the floor?
Work on the inside bottom first,
and then roll it onto the front-cowl/fire-wall,
and then POR and/or paint the bottom,
and then put the bottom down,
and then move on to work on the other parts of the cab.
This takes up less space, too.
