vulcantire.com sells falkens.

IMHO, the falken is much more versatile because it DOES work in the cold, and you can make it work well in the hot by cooling it. wheras with a normal high-temp tire, it works great in the warm, but theres no way to make it work in the cold. see what I'm saying?

:edit: if it were a track tire, it would be a totally different story, but for an autocross tire, falken is still the best option (with the exception of BFG KDs which are still too expensive to justify the price).