For finishing paint, I always use House of Kolor brand. I clearcoat that paint with a cheaper brand sold by NAPA.

Gelcoat is what is applied directly to the inside of a boat mold, that ends up being the outer layer of a hull once the glasswork is complete and removed from the mold. To learn more about gelcoat, and molds, even the paints you are asking about, I have a build thread currently going that demonstrates exactly how this process is done.
[link=http://www.rcuniverse.com/forum/m_7912646/mpage_1/key_/tm.htm]http://www.rcuniverse.com/forum/m_7912646/mpage_1/key_/tm.htm[/link]