I have no experience with epoxy other using to stick things together, and certainly not as a coating, so can't weigh in on that topic.

However, I will say that if you think you will carry on with this guitar building caper, it could be worth investing in some spray equipment.
You can even get by with an inexpensive airbrush for guitar work. It opens up the possibilities of finish materials, whether you want lacquers or poly, and you're no longer restricted to colour choices on the shelf.

Since you do surfboard building, you may already have a compressor. If so, you're half way there.
I've been spraying my poly exclusively the past few years and it makes a huge difference in the quality of the finish because you can apply a more consistent, controlled layer than wiping on or even a rattle can. IME, the coats can be applied a bit wetter (thus thicker) so you get a quicker build of finish. Even with my cheap eBay airbrush I get better results than I even got with wipe-on or spray can. I mostly use my touch-up size gun now (.08mm nozzle) but the airbrush is still handy.

When it cools off in the Autumn, I plan to spray two previous builds that have hand-applied poly finishes on them.