process of molding a widebody?

[philly blunt]

i decided on molding my widebody on for a cleaner look now the widebody is fiberglass so im sure i should use fiberglass-bondo instead of regular bondo for this my question is what type sand paper and what prep work is needed to do this i know how to do bondo and stuff im pretty good at that but i use a palm sander for bodo i dont think i should use that for fiberglass cause of different materials so i think i should use a sanding block correct me if im wrong