hi david, I am in oakland.  I think any good rehab and technology clinic
would be able to evaluate you, and they would know where to get the hand
controls.  The best rehab clinic is in palo alto, near stanford.   Or you
could call your local dept. of rehabilitation and ask them who they
recommend.  Another option is the Center for independent living in berkeley.

good luck!
mag, who drove for 21 years.