TPWK with nut flush draw (turn)

[LuckyDevil]

No reads, just stats over small sample size.
SB = 22/2/.75 over 50 hands
BTN = 42/20/1.8 over 60 hands

Poker Stars
No Limit Holdem Ring game
Blinds: $0.50/$1
5 players
Converter

Stack sizes:
Hero: $128
CO: $79.75
Button: $69.80
SB: $135.50
BB: $102.55

Pre-flop: (5 players) Hero is UTG with A[img]/images/graemlins/spade.gif[/img] 8[img]/images/graemlins/spade.gif[/img]
<font color="#cc0000">Hero raises to $3</font>, CO folds, Button calls, SB calls, BB folds.

Flop: 9[img]/images/graemlins/spade.gif[/img] Q[img]/images/graemlins/spade.gif[/img] A[img]/images/graemlins/club.gif[/img] ($10, 3 players)
SB checks, <font color="#cc0000">Hero bets $7</font>, Button calls, SB calls.

Turn: 4[img]/images/graemlins/diamond.gif[/img] ($31, 3 players)
SB checks, Hero ???

What is standard here? Also, what is standard if i had position on both of them and they both checked to me on the turn (IE if i was button and the other two were SB and UTG)?

[Dire]

Bet about $28. Your ace may very well be the best hand. The board is super drawy and they've done nothing but check, call. If you're behind then you stand to easily catch up on the river.