[Punker]

All three options are ok. In all actuality, his call preflop and bet of 600 on the flop is the much weirder play than your particular line. His bet leaves you in the dark as to whether he's betting small to try to steal it with a hand he's unsure is best and will fold to heat, or betting small to induce you to give him action with his monster.

After further consideration, I don't think the specific execution of your strategy really matters; after the flop comes, he's probably already decided whether he's going to play this hand for all his chips or not. It's just a question of whether you can somehow guess whether the answer is yes or no. If you think he's going to play for all his chips, you check fold. If you think he isn't, you somehow get all your chips in in any situation where he is not utterly pot committed.

So, ideal would be to play the hand in such a way to try to get him to give you that information as to whether he's going to play for all his chips, without exposing too many of your own; however, his stack is so short that you never really have a chance to do this in this spot.

So, whatever line you take will should be based heavily on his previous plays; he must have been mid-to-short stacked for a while. Has he been pushing in on steals, or repushing on raises, or cold calling raises, etc? If you don't have that information, what you do here is essentially a straight out guessing game, and given that he's put in half his stack already, I'm inclined to guess "he's going to play for it all".