Another source of good epoxies (System Three, a two-one mix) is Fiberglass Supply in Bingen, Washington. Google them for the website. They carry all the glass, carbon fiber, and kevlar you may need, along with cabosil (glass beads/powder, similar to microballons) milled glass fiber in several sizes, which is great for making strong fillets that won't crack later. The cabosil can be used the same way, and to make epoxy fills that will not run or sag when applied. They also stock the usual polyeste resin supplies, and all the accessories that someone may need.

Another thing about 50-50 mix hobby shop epoxies is that most of them are bonding epoxies and should not be used for laminating. They do ok with cabosil for thickening.