is the GTS a 6speed, or is it automatic? seriously......you dont want an auto GTS celica, it runs mid 17's. the 6speed GTS can hit 14's stock with a really good driver. there is a guy from california who has just intake, TRD clutch, drag radials, and apexi pfc, and hit 13.7 in the 1/4 mile......but dont expect to do this, because that guy is an ausome driver. he has hit 1.9 60' times, and for a celica without LSD thats crazy. ive got a 5speed GT celica with intake, header, and exhast and with crappy driving i run low 15.5's.
TRD makes a SC for the celica GT, and many companies make turbo's for both model celicas.
www.newcelica.org , or
www.everythingcelica.com have good info.
and incase you wernt sure......the current celica is from 2000-2004, and will include the 2005 when it comes out