AFAIK, the surfcaster body is mahogany, semi-hollow. The stock humbucker is a Duncan Custom - one of the vilest creations known to man IMHO :enforcer:
We're probably poles apart musically, but seeing as I've had the misfortune to have a Duncan Custom & hated it too, I'd say almost anything would be an improvement :)
Joking aside, why not a more "vintage" humbucker? If I'm reading your post correctly, you want something less "rock". How about a Stormy Monday?