I would recommend my shop, YimiSportTuning in Santa Clarita. Google the name for their address and phone number. The website doesn't get updated with content, but they are certainly reliable and busy with Subarus...they will not bullshit you. It may seem far, but I drive there from Ventura County if that's any consolation.
Honestly, I would not trust anyone's opinion in the Valley, nor would I trust any dealer in LA...
Good luck, I hope it's a good find!
70 to 100 faster than you can say "whoooossshh!"