I really don't like a re-raise here. I like a call. If you're behind you don't mind if the second caller has a flush draw, you welcome his call because if you improve it will be to the nuts. Obviously you can't fold since you're getting such great odds. Your implied odds are great, I would suspect that you stack the SB pretty often when you hit. Some small points...
1. When you bet on the turn you probably won't get respect for a big hand since it looks like either a steal or that you just hit the Jack. Ie: your hand strength is disguised.
2. Unless SB is a donk who's trying to buy the pot with a retarded move he has to have a big hand. I think it's weird to slowplay a straight, ever, but especially with a flush draw out. He gave everyone two chances to draw for free so obviously he's an idiot no matter what his holdings are, and will most likely pay off big time.
3. The button is probably very weak. Most SH players would bet the flush draw when checked to on the button, he could have a 5, a single pair or what not.
4. A raise will tell you where you're at against the SB (I'm sure you're ahead of the button) but you'd be in a really bad place if he comes over the top.
5. Why are you sitting with $750 and not a full buy in? Is this another one of those hands where you're one of the villains? Doesn't make sense either because you can't be SB (you wouldn't mini-CR) and any hand you'd be willing to call with as the button you'd bet on the flop (I would assume you'd have raised a J with a good kicker preflop so calling with TP as a bluff catcher on the turn seems unlikely). Did you lose a pot and not have time to reload? You said you just sat down.. something smells rotten...
Anyway... with immediate odds of 1:5 (1:6 if button overcalls which is likely) and implied odds of about 28:1 (51:1 if button is on the flush draw, SB has a lower set and you hit the
) I think it is an easy call.
River will be tricky but unless a heart, Ace or 6 comes I'd call a reasonable bet or valuebet if checked to.