Toyo Proxes (not Proxies dammit! ) T1-S are a nice tire. They're the spec tire for SCCA/Speed Channel World Challenge. Of course with the GT-class cars (450-ish hp to the wheel) you always see em sliding all over the place because even with huge sizes the realities of road-racing a 450-whp car on street tires overcome any goodness of said street tires. The TC-class cars (assorted Hondas, Proteges, IS300's, Bimmers etc) seem to be really fast on the tires though. Also take a look at the Bridgestone Potenza S-03. Pretty much the best out there.

Both of these are "real" maximum-performance street tires, so you'll notice a definite increase in stick and decrease in treadwear compared to the Kumhos. They should be fine for 12k miles though, probably a bit more.