got a reply from TWM:
"Thanks for your interest in our products. Fortunately you heard wrong, we do have a shifter which fits the 2003 GT. Part number TC0001SN will fit all GT model Celicas from 2000-2003. The GTS for 2002-2003 is a different part number however (though you don't have to worry about that)."
GREAT NEWS!! Thanks to Karel for the info