Gary's answer is a good one. I was also going to recommend First Republic. Gary or I could give you some good contacts there if you want to get in touch. I'd also check with Union Bank, another good local lender.
But an even more immediate option is to ask a Realtor or Title Company to check online tax records inside your building. We can often see what loans are against your neighbors' homes and what banks have done loans in the past. If you see a loan that looks like a refi, check on who did it and contact that lender. Chatting up your neighbors in the building to see if anyone else has pulled off a refi is another good way to do some research. Good luck!