All my boats got Glidden latex porch paint. I used Kilz latex primer for a couple, and Glidden latex primer for the other.
It is not the prettiest paint job I've ever seen, and is not scratch proof by any means, but durability has been reasonable, cost is about $20 per gallon, and application is easy.
You want to make sure that the surface is clean before you paint. Sanding is good, as is wiping with solvent. The waxy residue that can form when epoxy cures can be removed by wet sanding (sanding with sandpaper or a 3M brand sanding sponge and water). I don't know about what sort of waxy residue comes to the surface on poly resin; you would want to check the resin manufacturer website for that. They should have detailed info on prepping the surface for paint.
When sanding the surface, stop with a fairly coarse grit. You don't want a glassy smooth surface. With latex paint in particular, a "toothy" (slightly rough) surface will help give the paint something to grab hold of. Not so rough that it shows through the paint, mind you, but not glossy smooth.
Don't skip the primer. Primer is formulated to stick to bare surfaces and provide a good surface for finish paint to stick to. Finish paint sticks to the primer and provides appearance and durability.
My objective on boat paint is reasonable appearance and cost, and easy repair. My boats do NOT end up looking like showpieces. To get a really professional result, you would spend a lot more money and develop a lot better skills than I do.
Hope that helps.
ps - someone commented that you need to allow the paint to cure for a few days to get the full durability, and that comment is right - latex porch paint is very very tough (it is used for porches that get walked on, after all) but for the first day or so it is very vulnerable to damage.