West Systems epoxy can be used as a finish, I have done it in the past. It strengthens the wood and seals it, but it is messy and labor-intensive. I will only do this if a customer specifically says they want that type of finish.
If you want an easy to apply, tough, glossy epoxy finish, use Brownells' Acra-Coat-Wood ( http://www.brownells.com/.aspx/pid=1...ACRA-COAT-WOOD
). It is clear and glossy, and will only set you back about $25 ($14 for the finish, $10 for shipping). It sprays on, so even a schmoe can do it. The kind of wood you are spraying it on can determine how many coats you will need, but I have never needed more than 6 coats to totally seal and fill any stock. Once the stock is sanded and whiskered, I spray on a coat, let it harden up for a day or two, sand with 320 then 400 grit, spray another coat, let it harden, another coat, let it harden, sand with 400 grit until smooth, then 600 grit to really smooth it out, wipe it down with alcohol to take off any skin oils and dust, then another coat of finish, then polish. If the wood is really porous, add more coats and sanding until the grain is totally filled.
As far as polyurethane, they are pretty good, and easy to apply. Varathane spray spar polyurethane is probably one of the easiest and most widely available.