Try Litko's BaseMaker™ tool. Choose to have your base made from any of 20 different materials. You can even get special features like rounded corners on your bases.
Finally, somebody put out good quality wooden bases! These bases are well-cut and have a lower profile than Games Workshop bases, which I really like. If I have one small complaint it's that the slots can be a bit narrow, but that's easily taken care of with an X-Acto knife. The price is competitive and the shipping is reasonable. What's not to like? I'll definitely be ordering more of these bases in different sizes. Highly recommended.