I definitely recommend FFTEC in Hayward, they do great work but they've been moving to more expensive platforms lately (BMW, Porsche, GTR). Dave at FFTEC sometimes picks up work on the side, he's on BADSM/DSMTuners.
If you want to make the treck to Livermore/Dublin, I know the owner of DM Auto Salon and he's a Mitsubishi lover.
DM Auto Salon
3985 1st St Livermore, CA 94551
(925) 371-0100
Trenzy goes to some tuner out in San Jose I think. I believe the info is listed on DSMTuners. I'm not sure if he does repair.
I need to drop my transmission and swap my clutch soon.
I know a fair amount of Galant VR4 owners in the Bay and Sacramento now, we should do a GVR4 meetup sometime.