Haaah...his patronus is probably a doe, because I'm canon's bitch. >_>
BUT! It is not a doe because of romantic love, but familial love. Plus, all his happiest memories probably involve his childhood friend... Perhaps the patronus will change in time, however, after he makes some new memories with Remus. Then we would have to wonder what animal he'd associate with the man, since he says it wouldn't be a wolf. Ah, but perhaps that's a story for another day...