5/10 NL -- AJ faces shove

[private joker]

Live 400 NL, 5/10 blinds. It's late at night and the table is playing real wild. Routinely 7-8 to the flop, sometimes for a raise. Large pot-size bets are going in post flop and getting 2-3 callers. One guy is bluffing like crazy and showing it every time. Another guy is playing every hand and then doing fit-or-fold on the flop, never making moves.

I have about 350 in my stack, and I only cover 2 other players. Everyone else has a little more or a LOT more. 4 players limp to me on the button, and I limp with AJo (?). The SB makes a pot-building nuisance raise to 25. The BB calls 15 more, all the limpers call including me (?).

7 to the flop, pot=175.

Flop comes A74r. The SB checks, the BB checks, the bluffer checks, and a quietish player in MP -- one of the two guys I have covered -- shoves quickly and forcefully for 195. Folded back to me.

I'm pretty sure he raises AK/AQ preflop (well not sure about AQ, but he would have raised AK second in), and I think he's the type to slowplay a flopped set on a dry board. A7 and A4 are in his range, but I doubt 74s is. He hasn't been playing THAT loose, even though he likes to limp into a lot of pots. He can have AT-A2 as well, and possibly 65 though I haven't played with him long enough to know if he'd make this move.

Now, about the 3 to act behind me: SB is straight-forward, and his preflop raise felt like a KQs/JTs type hand. He either totally missed this flop or has AA. BB is the fit-or-fold donk. The other guy is the aggressive player who's been bluffing a lot, but he hasn't check-called any monsters as I've seen it.

I've got 325 left, so this is for 2/3 of my stack. Getting 2:1 on this call with 3 players behind me and the range stated for MP, what's my play here and is it close?