http://www.jamestowndistributo...id=64

Interlux makes good polyurethane paints and primers. Lot of prep work involved in painting over gelcoat.
Clean with a degreaser, sand, fill holes, gouges, prime, sand, paint.

Adding polyflake would not be a good idea if you are using the tip and roll method.

You will need to do this inside in a climate controlled garage or spray booth so the humidity does not affect the paint and to keep bugs/gnats off the paint while it dries.