Epoxy is tough stuff -- I've used it to coat wooden canoes that I've dragged all over hell and gone. I suspect it might yellow a little with long-term exposure to UV, but any top coat you add will be mostly about aesthetics.

I suspect that you could find a brush-on finish of some type, but it would look like ass unless you planned to wet-sand it flat, then to rub it out to a luster that you liked. That's easy to do, just a bit of elbow grease.