To be honest, I think it sounds like you might have the kind of kid who may not fit in particularly well anywhere. But if he's tested in the high gifted range, did you apply to any programs specifically for gifted students?
Have you considered whether you'd do just as well to send him to public school? I know private schools are crazy popular in SF, but that doesn't mean that they're a better choice for everyone. Not everyone's going to be able to afford to live in SF and pay for private school, and you're in an area that imports a lot of highly skilled workers; I'd think there's a good chance a lot of very intelligent kids end up in public schools (especially since it sounds like anyone who moves in after preschool would be hard-pressed to find a spot in a private school).
