€15 live: Too thin to block-bet river?

[mr.spam]

Local game in bar, we started with 11 people so two tables first, one of 6 and one of 5, first 3 pay. Starting stack is t10000, blinds at 25/50, second hand of the game so no read on villain (never played with him before) and I just took the blinds from an UTG raise. I'm at the six-handed table.

Hero's stack t10075.
Villain's stack t10000.
2 folds, Villain raises to t200, 2 folds, Hero calls from big blind with A [img]/images/graemlins/club.gif[/img] 8 [img]/images/graemlins/club.gif[/img]

Flop: Q [img]/images/graemlins/club.gif[/img] 9 [img]/images/graemlins/club.gif[/img] 9 [img]/images/graemlins/spade.gif[/img] (pot t425)

Hero checks, Villain bets t300, Hero raises to t1000, Villain calls.

Turn: A [img]/images/graemlins/diamond.gif[/img] (pot t2425)

Hero bets t1400, Villain calls t1400.

River: 4 [img]/images/graemlins/heart.gif[/img] (pot t5225)

Hero bets or checks?

Blockbet seems ok, though I can't think of a lot of hands that he calls with that I beat. Maybe KK (or a Q if I don't bet too much). If I check he may bet AQ and any 9, but maybe stuff like JT or KcTc or some other (combo-)draw. If bet, how much? As played I checked though I don't know if that's the optimal play here... Comments on other streets appreciated as well of course.