Anybody know where I can find these? For testing future fins on raceboards before i decide to pot them?

Its super easy to make your own. Simply pot a set of these into a tuttle bases. As for an actual use for course racing, There are no future fins that currently will go head to head with the windsurf fin technology used in racing. They are simply too small. Slalom or crossings however, this is a good option. I did this myself as well.