What Primer????????

I am in the process of restoring/refinishing a fiberglass jon boat. I bought some Sea Bowld Top Gloss Polyurethane Enamel to paint the interior with. It currently has paint in it, it is just old. Is sanding it and then wiping it down with acetone or something like that sufficient or, do I need to prime it first? If so, what is a suitable primer?

Thanks