Need 1 hitter, who to trade? WHIR 100%

[Hit Factory]

Hey I am in a 12 team 5x5 roto league, and I have been pondering this since the start of the season. I would like to get another hitter in exchange for 1 of my pitchers. Please help me out, who do you think I should trade and what player do you think I could get back in return? I have been thinking about this for awhile and my brain is fried haha! WHIR 100!! Possibly Cain for Corey Hart?
Here is my current team:
Posada
Dunn
Kelly Johnson
Youkilis
Khalil Greene (not many solid ss's this year.)
MI: Aaron Hill
CI: Mike Jacobs
Sizemore
B.J. Upton
Carlos Lee
Dye
Util: Cust (this is where I would like to upgrade)
BN: Ben Zobrist
BN: Hank Blalock

Hamels
Billingsley
K-Rod
Wood
Cain
Slowey
Rafael Soriano
Anibal Sanchez
BN: Trevor Cahill
BN: Mark Buehrle
DL: Dice-K