Gutshot Straight + Flush Draw on Flop

[Atropos]

Party Poker No-Limit Hold'em, $ BB (6 max, 5 handed) converter

Hero ($95)
Button ($54.85)
SB ($93.4)
BB ($145.9)
UTG ($104.95)

Preflop: Hero is MP with 9[img]/images/graemlins/diamond.gif[/img], J[img]/images/graemlins/diamond.gif[/img]. SB posts a blind of $0.5.
<font color="#CC3333">UTG raises to $2</font>, Hero calls $2, <font color="#666666">1 fold</font>, <font color="#CC3333">SB (poster) raises to $4.5</font>, BB calls $4, UTG calls $3, Hero calls $3.

Flop: ($20) 3[img]/images/graemlins/diamond.gif[/img], 7[img]/images/graemlins/club.gif[/img], 8[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">SB bets $20</font>, <font color="#CC3333">BB raises to $125</font>, UTG folds, Hero ???

This hand seems strictly mathematical to me, however I dont know how to crunch the numbers. Here is my try:
- BB was a crazy maniac who seemed to have no idea of proper poker. But he was rather passive, so you cant put him on a stone cold bluff there. His range of hands was still unclear to me, I would consider Two Pair/Set/Overpair/TPTK/Straight Draw/Flush Draw... However the last 3 are rather improbable.

He was so bad that I would not mind losing my stack on a 50:50 situation against him, because it seemed I could easily get them back against him. Maybe even a 40:60 situation thus slightly -EV would be ok there...

- The SB was rather tight preflop, not soo good postflop. His range preflop is pretty much AK/AQ/AA-TT, maybe some more hands. At the flop I expect him to fold everything except AKs/AQs right suits. But it is still possible he would call with AA+KK there too.

OK lets consider that SB will automatically fold:
- There is 40$ dead money in the pot. I have to put in 90$ to win a pot of 220$ (2x 90$ + 40$, is that wrong thinking?)
So my "break-even point" would be a chance of 40.9% to win.

Some scenarios:
- J9s against BB's two pair: ~ 45% : 55%
- J9s against BB's set: ~ 33% : 67%
- J9s against BB's Overpair: ~ 47% : 53%
- J9s against BB's Straight Draw: 81% : 19% [img]/images/graemlins/smile.gif[/img]
- J9s against BB's higher Flush Draw: 27% : 73%
- J9s against BB's TPTK: 57% : 43%

Against BB alone I seem to be in very good shape. Putting him on a very bad range of hands for me, 50% two pair and 50% set I would be around 39% chance of winning. Thats of course -EV but only marginally, and because he is so bad the chips are worth to him less than to me. I think against him I can safely make the call here...

Now there is the problem that SB has yet to act. The hands I fear most are AKs and AQs of the right suit, they would kill my chances of winning. There seem to be no other hands SB has that could kill me in this pot.

OK how I want to know:
a) Do you like a call here?
b) How do you explain it? How do you compute the chances of SB having AKs/AQs right suit, chances he will call with AA/KK and make an overall model for my equity in this hand?