For Cali, I would recommend staying in two spots which are relatively close around LA, but have dif vibes. Stay at the Viceroy Hotel in Santa Monica, just North of LA, lots of stuff doing on in the low brow art scene that I think you would like Tom, plus you can check out Venice Beach and the whole Dog Town thing (rent Z boys before you go), plus you can go to Supreme and other indi sneaker collector shops.
The second spot I would go is just south of LA, Huntington Beach, where you can get that whole rich kid who drives a BMW and surfs all day feel and girls that where bikinis 24/7 with a $100 trucker hat… ahh Cali.
In the middle, make sure you pop into the Standard Hotel in LA for some drinks, you will most likely see someone there you have only seen on TV, last time my friends where there, The Kills where chilling at the pool.
Let me know if you go to LA, I have some friends down there you can party with. Heres a list of a few good shops:
http://superfuture.com/city/city/selected.cfm?city=9
I think Miami is also a good spot to hit (and less flight change overs for you probably) stay in the Shore Club or the Delano, the art Deco district is pretty cool. Some good vintage American modern. And the people watching is great.
I’m not a huge San Fran fan, it’s OK, good collector sneaker culture, art acene is a little snobby IMO, at least what I saw… I hear Santa Cruz is pretty sweet, just 1.5 hour drive South od San Fran.