Well considering the GTS weighs about 600 pounds less it is likely that it would be faster once moving. However, like many have been pointing out the GTS hasn't been know for its reliability and tunability. The only two cars I'd consider in that price range are the ITR and WRX.
Edit, and like Andrew was pointing out, it seems that all you want is acceleration and speed. So you really should look into a camaro or firebird. Those things can be had for cheap and will hual ass.
[This message has been edited by Eby (edited February 17, 2001).]