Current Wheel setup:
Front:
17x8 40mm offset Konig Monsoon
Kumho Ecsta MX 235/45/17.

Rear:
17x9.5 49mm offset Konig Monsoon
Kumho Ecsta MX 285/40/17

Click here for the wheel fitment guide for the Supra... Should  be close or identical to the SC300.