KJo river quandary

[Ponks]

Wasn't really sure how to play this hand here. As I said in my previous post I just started playing short handed yesterday. I'm trying to improve my short game so I can more comfortably beat the 15/30, not to mention that I've found out 6 max is good fun/profits (so far atleast!). I also notice I'm getting reads better on players when I'm playing 6 max. SB in this hand is very aggressive preflop and pretty aggressive on the flop but slows down on the turn and river. He 3-bet once with T7s and has raised a lot with hands UTG and UTG+1 I wouldnt even play from the SB. The BB is pretty aggressive as well. He's not afraid to play back at anyone. That's about all I had so far in the session. Also if you'd play any of the other streets differently let me know as well. How's the turn check?? I'm normally pretty aggressive with overcards when I raise preflop, but this looked like a good spot to check the turn. Also whats the most profitable play on the river?

Party Poker 5/10 Hold'em (6 max, 5 handed) converter

Preflop: Hero is MP with J[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/heart.gif[/img].
<font color="666666">1 fold</font>, <font color="CC3333">Hero raises</font>, <font color="666666">1 fold</font>, SB calls, BB calls.

Flop: (6 SB) 7[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/heart.gif[/img] <font color="blue">(3 players)</font>
SB checks, BB checks, <font color="CC3333">Hero bets</font>, SB calls, BB calls.

Turn: (4.50 BB) 4[img]/images/graemlins/heart.gif[/img] <font color="blue">(3 players)</font>
SB checks, BB checks, Hero checks.

River: (4.50 BB) 6[img]/images/graemlins/heart.gif[/img] <font color="blue">(3 players)</font>
<font color="CC3333">SB bets</font>, <font color="CC3333">BB raises</font>, Hero ????

Final Pot: 10.50 BB
<font color="green">Main Pot: 10.50 BB, between SB, BB and Hero.</font>

Thanks
Ponks