Hi folks, my first post here but i'll been reading about sanding/painting cars for weeks now. My grandson wants me and him to paint his jeep wrangler i gave him for his 16th bday when schools out for the summer. I have painted lots of cabinets and things around the shop like camper tops, tractor, trailer, etc.but no complete car. We will be changing the color from dark green to a med orange. The jeep is in real good shape for its age with only alittle clear coat coming off on the one fender about the size of a dollar bill. My question is what grit paper do i need to start with on a 6" DA sander to get it ready for primer? They is only 2 small dents on the hood( which has been painted since new) bc/cc, the rest of body is straight and rust free. I'm thinking of going with acrylic urethane sc or bc/cc. Any thoughts on the paint would be helpful also.
The gun i'm going to use is old school devilbiss JGA 502. This will be my last complete paint job, so no new gun for me. Also any thoughts on how much primer/paint i would need for this small jeep.

Thanks for the great site to help people like me and grandson.