Thanks Daniel, I use a 55mm balanced flycutter from Carbitool, it was about $200 USD, but it is balanced and the tips on the end you can rotate once they become worn, so you can get 4x the life out of it, and obviously they are replaceable at a fraction the cost of the original tool. Being that it is 55mm you can surface your spoilboard in no time at all
http://s28.postimg.org/p9obg8ca5/Flycut_Tool.jpg
Cheers
Lee