PP 15 against a donk

[Dazarath]

Villian is a donk with stats 39/22/1.88 over 1200 hands. Just in the last few hours, I've been on maybe 3 of the same tables as him, and he's played a lot of hands this way, including things like 9 high, 44 as an underpair, and once a set. My question is, how many bets should I put in maximize the amount I get when I'm ahead (which is like 80% of the time), but to also try to keep losses to a minimum in case he flopped a monster?

Party Poker 15/30 Hold'em (9 handed) converter

Preflop: Hero is UTG+1 with A[img]/images/graemlins/club.gif[/img], A[img]/images/graemlins/diamond.gif[/img].
UTG calls, <font color="#CC3333">Hero raises</font>, <font color="#666666">3 folds</font>, CO calls, <font color="#666666">2 folds</font>, BB calls, UTG calls.

Flop: (8.66 SB) T[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/diamond.gif[/img], 8[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
BB checks, UTG checks, <font color="#CC3333">Hero bets</font>, <font color="#CC3333">CO raises</font>, BB folds, UTG folds, <font color="#CC3333">Hero 3-bets</font>, <font color="#CC3333">CO caps</font>, Hero calls.

Turn: (8.33 BB) 8[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">CO raises</font>, Hero calls.

River: (12.33 BB) 6[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, CO checks.

Final Pot: 12.33 BB