Check out this guy below from UK, he has a lot of used GT / GTS parts: I've purchased off him before and he's cool.
Nick (nic name on NewCelica.org is Carbons)
1970 Celica GT - 275,000 miles - retired
1980 Celica GT - 350,000 miles - retired
2003 Celica GT - 171,000 km's - Being Sold
2004 Celica GTS Tsunami - 151,000 km's - driving