Your boat is made from polyester resin. Using polyester resin, mat, and cloth/fabric will yield MORE than acceptable results. Not All Gelcoat is the same. Some MIGHT adhere well to epoxy coatings others Not so Much!!! Gelcoat is a Polyester resin based product, and therefore is made to adhere well to Polyester resin coated surfaces. I'd HIGHLY recommend that you use Polyester Resin for your boat repairs. The difference in it's water resistance and that of epoxy is very minimal. Epoxy IS stronger and WILL stick to just about anything, but..IMHO it's hard to work with due to the long Tack time and Cure time. You can get things done so much quicker using Poly. I KNOW what the epoxy guys say, and I would too if I were making a living selling it. This forum has plenty of success stories proving that Poly Resin will get the job done and done well!!!
When you're ready to do the repair, we can/will point you to other threads that have done it and you'll see just how easy it really is.