16: Well concealed hand river play

[Velocity]

He sure as hell doesn't put me on a jack. He may not even put me on a hand at all, just look his own and choose a button.

PokerStars Tournament, Big Blind is t50 (8 handed) Converter on pregopoker.com

UTG (t1140)
UTG+1 (t1200)
MP1 (t1585)
MP2 (t2170)
CO (t1485)
Button (t1450)
SB (t3130)
Hero (t1340)

Preflop: Hero is in BB with 5[img]/images/graemlins/club.gif[/img] J[img]/images/graemlins/club.gif[/img]
UTG calls t50, <font color="gray">UTG+1 folds</font>, <font color="gray">MP1 folds</font>, <font color="gray">MP2 folds</font>, <font color="gray">CO folds</font>, <font color="gray">Button folds</font>, <font color="gray">SB folds</font>, Hero checks

Flop: (t125) T[img]/images/graemlins/heart.gif[/img] 6[img]/images/graemlins/diamond.gif[/img] 7[img]/images/graemlins/spade.gif[/img] (2 players)
Hero checks, UTG checks

Turn: (t125) 4[img]/images/graemlins/club.gif[/img] (2 players)
Hero checks, <font color="red">UTG bets t100</font>, <font color="red">Hero raises to t300</font>, UTG calls t200

River: (t725) J[img]/images/graemlins/diamond.gif[/img] (2 players)
Hero ????
Lead for 300ish? Shove? Check/call?