Not sure you are gonna be able to do better than Upton; the list is mighty small for who can be traded for Zimm straight up IMO. I would say to target the team's best OF that has Aramis Ramirez and see what you can get out of that (if that team happens to have Soriano, even better).
Thanks for your reply in my post.
C-BMolina 1B-Votto 2B-Utley 3B-Youk SS-Furcal LF-JDamon CF-BJUpton
RF-ARios UT-DLee BN-Scutaro,CBlake,Schumaker DL-JReyes
SP-SBaker RP-ABailey P-Saito,Hawkins,JJohnson,Dempster,Danks,JShields,Garza