If you're looking for a super fair, smooth, glossy finish (aka museum finish), you could use a high build primer and a long board to sand it down fair.  I'll probably do that since my scarf joints didn't turn out so smooth. 

On my Eastport Pram, since there were no scarf joints to fair, I was able to paint directly onto the epoxy.  I used Pettit EZPoxy with no thinner, but rolled and tipped it with foam brush.  It turned out great, but you can see some artifacts telegraphed through the paint that I missed.  It's pretty glossy.

Jim,

Primer performs two functions - it fills pinhole-sized defects and provides a surface that paint will stick to. If the defect is larger than a pinhole, use fairing compound to fix it. Thick layers of primer are too soft.

As far as needing primer, first check to see if your paint is compatible with epoxy. If it is, you don't need primer to make it stick. Otherwise you do.

The way you'll be using your boat, topside paint is fine. As for brands, Brightsides (sold on this site) is a good one. I've also had good luck with System Three products.

Have fun,

Laszlo

Leaning toward something maybe a little closer to what Phil Bolger might have described as "fisherman finish" rather than "museum grade", we used Behr Premium porch paint (based on the recommendation of a boat builder I know) on our PMD, glossy white for the exterior and a color they called "cold lager" (a warm sort of tan shade) low-lustre for the interior.  Applied with rollers and foam brushes; cleans up easily with water.  Available at Home Depoot.  Varnish was minimal, just on the transoms.

We applied on the epoxied surfaces without any primer, and it has worked out okay.  It is holding up well, and it is easy to touch up the dings and places where it wears.  I bought a decent set of artists' brushes in various sizes to help with the touch up--easier to feather out the small places so it's less obvious where it was touched up.  Easy touch-up was mainly what we were after in going this route.

Like I said, maybe not exactly yacht finish, but it looks good enough to place in a few of the monthy CLC photo contests and have some of those entries show up in the PMD photo galleries.  It's all according to how much money you want to spend, how much time you want to put into it, and how close you want people to look.  <;-)

.....Michael

   I went with what CLC recommended, and couldn't be more pleased. Interlux PreKote and Brightsides. I'm far from an artist, but quickly learned the "roll and tip" technique. I have to say this finish looks fantastic.