If it were me, I'd take Peterson in a heartbeat. Between him, Vick, Norwood, and our zone-blocking scheme (if we don't stay with it, we might still use stretch plays here and there), our running game would be unstoppable for many years. Peterson is another RB in the mold of Stephen Jackson and Larry Johnson who can dominate a game. Put him in our zone-blocking scheme, and he'd be ridiculous. Sure, he might have some injury issues occasionally, but that's why you keep two RBs around all the time. Platoon them both.
I think the left side of the OL needs retooling. Don't mess with Forney or Weiner and maybe leave McClure alone too. But Gandy should be a cap cut and Lehr just isn't getting the job done. Bring in someone who has some talent in FA and the draft for LT and LG, and see how things turn out. If we don't get a chance at Peterson, I'd say take Blaylock and put him at LG. That guy is going to be a stud for a long time. You can use any blocking scheme with him and he'll produce results. Then we find a solid LT to keep DEs out of Vicks face. Gandy did ok at that this year, but it might be time for us to have someone who can dominate there. Then a new offensive scheme and we're back in the hunt.