I think most air DA's have a way to work in both actions but I don't 'know' it for any but mine.
A Circular is faster at stripping but a DA leaves less of a scratch pattern. I guess that's why they make em that way?
If you have a variable speed buffer like a Makita or something you could use it. a screw gun/drill will do for a roloc disk.
I screwed and glued a dewalt 5" hook and loop pad to my old porter cable that took 1/4 sheet and like it better than either one before. I use it more than my air DA now when I'm finish stripping.
Figure out a process that works for you that's easy to repeat.
For my working comfort I pulled the panels and set them on saw horses or whatever worked.
A plywood panel bolted to an engine stand can hold doors or fenders. I had both rears mounted on a piece of 1/2" ply I traced and cut to fit the profile. Since my bed was off, I had it setting on a piece of plywood across the back of the truck. It was accessible from the ground or standing up on the plywood.
