I'm currently running on KYB AGX dampers with RSR Race springs. I absolutely love the setup on the track, but the damping leaves a little bit to be desired. A friend of mine is going to be putting in Tokico Illuminas with his RSR Race springs and we're hoping that'll be a better solution.
The Race springs have a huge spring rate. If you want a ride that's still even more stable than stock would provide but keep the ride quality up I would suggest that you check out RSR Downs and look at either the Illuminas or perhaps Koni Yellow dampers. H&R springs are also very commonly used in the autox community but they're a little more expensive.
www.horsepowerfreaks.com is where I bought my springs. Had a very positive experience with them. Make sure that you call and talk to 'em instead of just ordering online. The bigger package you purchase (springs and dampers) the better deal you can get from 'em.