NL 5/5 Live Turned Top Two facing a donkbet

[HustlerLA]

Hero BTN ($1000)
MP($600)
SB ($700)
1 MP limper and Hero dealt A [img]/images/graemlins/spade.gif[/img]Q [img]/images/graemlins/spade.gif[/img] on BTN and raises to 20. SB calls, MP calls.

No major player reads except that SB isnt a habitual bluffer, may overvalue hands and bet believing he is ahead though. Cant remember now if this was before or after this hand but for this post lets assume before, he c/c a flop bet from me and then donked a PSB when the flush draw completed, I folded and he showed the flush. MP limper is super fishy call station.
Flop Q [img]/images/graemlins/club.gif[/img]4 [img]/images/graemlins/spade.gif[/img]T [img]/images/graemlins/heart.gif[/img]
SB checks, MP checks, Hero bets 40, SB calls MP calls.
Turn Ac. Pot$220 SB bets 100, MP folds, Hero?