Then what Peter said. I've used both for my R/C glider. You should still be able to use the transtint with the standard stuff. Since you are near the water, should be easy for you to find as well.
If you don't want it to be as hard, you have to adjust the mixture. Really can't tell you which way to go, but I have screwed up batches before and ended up with a rubbery epoxy.
Instead of 50/50, go 60(resin)/40(hardener) or less. Should make it more pliable.