Any recommendations regarding type of sander and grade
of sand paper? I

I painted my Eberly, Libelle trailer top a few years
back. Sanded it with 60 grit on an 18 inch air-board.
Cheap air-boards are available for under $100 bucks,
but you need a source of high volume air at about 90+
PSI. Then I painted it with synthetic enamel with flatner
added so that the gloss wouldn't show all the imperfections
in the fiberglass and also my 60 grit sand marks. Looked
good and has held up well.
JJ