I refinished my 18-footer SR canoe, it worked spectacularly well. I learned a couple of things:

1. Methanol in a spray bottle works really well for cleaning
2. A large brush worked better than the 5" roller - as the epoxy gets thicker (only takes about 15-20 minutes in 30C weather), the roller clumps the epoxy and then you really can't "unclump" it. Did not have the same problem with the brush.

Moving onto a friend's 17-footer SR canoe. He bought it used from KO a few years ago.

Edit: just heard back from KO. They use the West 105 epoxy, so this will be easy!!

http://killarneyoutfitters.com/refinish_kevlar_canoes.php

Reading the interwebs, seems like epoxy over varnish is doable, but not recommended for long-lasting finish (flakes).

Thanks!
Marko