The Bandit should use a 12mm hex. I know the Rustler and Stampede do.
I got just the thing you're looking for. These are the actual Traxxas tires made for asphalt. Proline also makes some too. I believe you could get away using any 12mm hex wheel (2.2) but i'm not sure on that one as I don't own a bandit.
Rear
http://www.google.com/products/catal...d=0CF4Q8wIwAQ#
and
Front:
http://www.google.com/products/catal...d=0CGYQ8wIwAw#