What about Humanoid-wake's fins? they are "made of 100% REAL urethane and have a tiny bit of flex to them. No more splitting, shattering then sharding! ARRRR!" and they come in 3 different colors. cool
http://humanoidwakeboards.bigcartel....duct/ahoy-fins
f.y.i. not a rail guy and have never used these fins, but they have a nice blunt design and different material than pretty much anything out there.
there is also CDIfins.com BUT they are all aluminum, and i think most parks don't allow alluminum no matter the shape right? Anyway. i have the low pro fins from cdifins on my slingshot. .7 inches. pretty much the shallowest fin i have ever seen. i like it for the loose feel on the water. they have a really blunt edge to them and the base is really wide to spread out the pressure when boting them to the board. pluse the shine of the fins looks great IMO