For soft surfaces usually the best race tires are step pins. Team Losi has them and also Pro-Line which has step pins as well as lug nuts which are similar but with a different lower step for better support of the top pin. The tires you mentioned are good all around, bashing type tires. They wouldn't work nearly as well on a track as step pins would. Before you drop the money on new tires I would take a trip to the track first to see what the fast guys are running. Also, just get new wheels with the new tires. That way, you don't have to use your racing tires for bashing and just add wear to them.