You'll find this is predominantly a U.K. site, although there are a number of us Norte Americanos that stop by from time to time. But for location specific questions such as this, you may not receive many suggestions. I live in the inter-mountain west and, although I've been in Sacramento several times, I've had no experience with insulation.
I would suggest, however, calling, of all people, you house insurance company. We had to have our attic re-insulated after some leakage and our home owner's insurance company (State Farm, by the way) who had to pay for most of it, offered some good suggestions for quality work.
Best of luck!