Many thanks, Mowgli. That clears up some questions (I had wondered how multiclassing worked - sensible solution).
My dream build at the moment is probably a Summoner//Lore Warden, with a bipedal, polearm-wielding eidolon. I think that'd be hella fun, but I also recognize that that'd be encroaching on Satin Knights' territory. So I'm trying to find alternatives.
I had thought of a Synthesist//Fighter (Brawler), but I'm not convinced with the character ideas that I've had associated with that sort of a build. So I'm still thinking.
I've had the idea for a switch hitter alchemist for a while, but I'm not sure if I could pull it off satisfactorily with a 15 point buy, although obviously gestalt helps a bit on that.
Edit: also, I'm curious - if choosing two spellcasting classes isn't allowed, how do we have a Summoner//Cleric and Sorcerer//Bard?