Flinter42 also has a good used carb for sale. Check the 'for sale' section. His carb already has the TORS delete kit installed, and nobody has laid claim to it yet.
Also, if you want to upgrade, go to ebay and get a used Keihin PWK off an 85cc dirtbike. These carbs can be had cheap as long as you know to re-jet before running one; I was on yesterday and saw one for $ 79.99 in good condition...