I would min-raise or to 6000. I would be surprised the SB has the flush, maybe 2 pairs or top-pair or likely a combo. By min-raising, the flush shouldn't call and if they do, you can go all-in on the turn giving them a second chance to fold if they don't hit. Also, if an Ace comes, they will stick to it and you will win more. By min-raising, you will get called at least by the SB and it will be easy on the turn or river to extract more money (don';t push and make him fold).

What about the results?