I bought my tumbler at the dealer. It wasn't as inexpensive as Fast Lane, but they were able to order it matched to my existing key.
To remove mine, I followed the instructions posted here, but I used a wire hanger instead of the special tool. If you go the wire hanger route, be sure to file the end at an angle similar to the real tool. (Someone posted an illustration.) Otherwise you'll never get it. It took me about 10 minutes of cursing to get it out, but once you do the rest is easy. You can start the car with a screwdriver if need be while you're waiting for parts.