9.5s will work all around as illustrated by First-SHO's setup:
Forgestar F14's 20 x 9.5 all around with Nitto Invo 275/40-20's.
Offset +36 Front and +42 rear.
20x10 will work in the rear as illustrated by bpd1151's setup:
20x10 TSW Nurburgring wrapped in 275/40 ZR 20's (Continental Extreme Contact DWS's), 40mm Offset.