Generally any kind of automotive paint
will work just fine on fiberglass, plus it is made to be polished and waxed. I ran into a problem using a paint
by Interlux made for fiberglass - Brightsides. It can't be polished or waxed, as it instantly loses its shine, and can't be overtopped by much, if anything. I painted the deck of my classic boat with it, and am in the process of trying a few different things to overcoat it with something that can be polished and waxed.
Are you having it sprayed, or doing it with roller and brush? If roller and brush, one of the best all around paints out there is good old oil-based Rustoleum. Prepare your surface well, keep the surface uber clean, and thin the paint for your 1st coats. It requires a lot of elbow grease, color sanding and buffing, but can work if you have the time.
You really can't beat UV-protected car paint, generally base coat/cl;ear coat. It will give you the longest life as long as you take care of it.