What I am really looking for is a good solution for kayak interiors. Refinishing a kayak exterior is really not very hard, but the interior is a really a hassle. Since it does not get as much UV exposure an epoxy that handles a good bit of UV for awhile would be a nice solution.

I don't understand.
You are referring to the interior of a sea kayak? I can see the problem with 'no-skirt' semi-canoe style kayaks, but the interior of my sea kayaks just don't get much UV exposure. When paddling, the sprayskirt/spraydeck shields the cockpit interior; when transporting, there's usually a cockpit cover snapped over the opening. I store my boats in a shed.

That said, I generally use an opaque coloring agent (black iron oxide) in the epoxy on the cockpit interior, but that's for cosmetic reasons, not UV protection. In the compartments, I add white pigment (System Three) to make the inside lighter - I got tired of missing small items in the boat ends.