I actually bought my car from a guy in Redding, and he did all of his work in the bay area/Sacramento. If it were me, i would go to GST Motorsports in Hayward or EQ Tuning in Fairfield. Me personally, I get my tuning done at EQ and my mechanical work done at GST. From my experience, FW motorsports in Sacramento (Rocklin) is a little shaky. Instead of taking the time to diagnose a problem, he threw random parts at my car charging me out the ass for something that took GST litterally 2 hours to figure out.
For the most part, shops may have you sign a document stating that they are not liable for any tickets/ legal action against you for putting on illegal modifications. Thats it. No big deal. Good luck and choose your tuner wisely!