Hi! We are in the Bay Area too, and I think language immersion is a FANTASTIC option for advanced kids here. My son was reading fluently at 3-4 and we chose a Spanish Immersion program for him (public school) and he has done well and enjoyed it so far. I would not recommend skipping K - its so much fun! They sing, do silly crafts, go on field trips and have enormous amounts of playtime, all of which DS loves. 1st grade seems way more grim, in our school at least.
Also, not sure which district you are in, but ours is vehemently opposed to early entry and grade skipping. Its much easier to get into the system and then have the teachers and principal working for you. A new parent coming into K registration claiming their child is too advanced for K would be rudely brushed off in our district (with some justification - they see too many cases of this every year)
