Both villains i have no history with. CO is running 25/21/2 over 60 hands and SB seems spewy and loose running 35/22/2.6. I'm pretty sure i should bet the turn but how much and what's your plan against all scenarios?

Full Tilt No-Limit Hold'em, $4 BB (6 handed) Full-Tilt Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

Button ($400.10)
SB ($464)
BB ($92)
Hero ($431.90)
MP ($268.60)
CO ($411.30)

Preflop: Hero is UTG with A, A.
Hero raises to $14, 1 fold, CO calls $14, 1 fold, SB calls $12, BB calls $10.

Flop: ($56) 9, 6, 8 (4 players)
SB checks, BB checks, Hero bets $40, CO calls $40, SB calls $40, BB folds.

Turn: ($176) K (3 players)
SB checks, [color=#CC3333]Hero ????