hand #1 from 5000 PLHE

[2005]

Having already lost a big pot with AA I am down to less than 1600 chips, blinds 25/50. Villain in the hand and I got into an argument about how he thinks online poker is rigged to create action before the tournament started. He has been calling my raises alot and has made alot of river bluffs so far.

I'm MP1 with AQo(both black) and make it 150. Villain and button call, both blinds fold. Flop is K73 rainbow, it is checked around. Turn is the 4h, putting 2 hearts on board. I check, villain bets 500, button folds, I call. River is an offsuit 7, I check, he bets 1000, I have 975 left. What do you put Villain on, and should I call all in with nut no pair?