I can't tell where you are, but if it's in the US or Canada try here:

http://www.americanmototire.com/catalog/

Best prices I've found.

Steelheart- '03 Speedmaster Black/Yellow The Hayabusa Killa 16" Shorties/140 mains/Airbox drilled Procom CDI "There is no cure for Celibacy. But we can treat the symptoms."