Are you running at Universal? If so the first thing I would suggest is at least trying the truggy Blue springs. IMHO, the silvers are far too soft for carpet. Silvers are a good all-round dirt spring. I believe you said that you tried the Purples or the Pinks? I believe you said you did not like the car with those stiffer springs? (sorry if I am confusing you with someone else.)
I would try stiffer springs (at least the Blues, I personally would try the Purple or Pink), stiffer sway bars, a little lower ride height, and the aluminum braces front and rear should help too.
In general, I really believe stiffening up the whole car should smoothen out the cars dynamics making it easier to drive. Ya gotta be able to slide a little! It will probably feel weird at first because the turn-in won't be as violent and it should be less prone to traction roll.
I recently tried putting the stiffest front spring available for my "non-XRay" 1/10 scale 2wd buggy and man it really smoothed out the steering response and made the car a little easier to drive. Now if only it could go more than 2 laps without destroying the ball diff!
Regards,
Speed Metal