3-Flush on the Flop with Top Pair, what's your play?

Had an interesting hand this past weekend in Vegas:

MGM $1/$2 NL ($40-$200 buy-in)
10-handed
relevant stacks:
SB ($185)
UTG ($10)
MP3 - Hero ($350)
MP4, CO, B (>$400)

Table had been generally loose/passive, occasionally becoming very loose/aggressive (including on the previous hand). SB (Villian) was fairly new to the table but seemed to be a competent, experienced player.

UTG goes all in for his last $10. He was a weak player and had just lost almost all of his chips on the previous hand. Despite the small blinds, $10-$15 was a standard opening raise at the table.

Folded around to me in MP3. I raise to $25 with A[img]/images/graemlins/diamond.gif[/img]Q[img]/images/graemlins/diamond.gif[/img] to isolate, mostly to avoid having to play OOP against the 3 stacks behind me who have me covered.

Folded to the SB who raises to $50. BB folds. I ask SB how much he has left (his hand is blocking his chips) and he says he has $135 behind but does not move his hand to show me his chip stack. I call.

$32 in the main pot, $80 in the side pot.
Flop: A[img]/images/graemlins/heart.gif[/img]J[img]/images/graemlins/heart.gif[/img]6[img]/images/graemlins/heart.gif[/img]

After a couple of seconds, SB bets $100.

- What range of hands do you put the SB on?
- What would you estimate your pot equity as given your read on SB?
- What is your play on the flop: All-in, Call, or Fold? Why?

i'd fold but i'm a puss.

Why would you fold, though? What hand/range of hands do you think the SB has?