I have to agree with Jeremy, it's not easy to locate property based upon it's archetectural style. Lucily, Spanish sylte homes are plentyful in Southern California, so you shouldn't have too much trouble locating them on the MLS> Craftsman, on the other hand seem to be located together, in certain older neighborhoods. In Los Angeles area that would be Venice,Inglewood, and some pockets of Larchmont, and WLA.
I would sugest the older areas of Ontario, as a place to start. Access the MLS with no obligation from my website below.