Stefen Wisniewski would be a reasonable FA signing that I'd like a lot. The kid is in his mid 20's, he can play all three interior O-line positions, & the Bears need a new Center now. IMO, DLP & Garza have been underwhelming, & now it looks as though there could be a possibility that the Bears will have to address the starting O-line again, outside of the Center position. Signing Wisniewski would let Emery focus on using his draft picks for fixing the defense, & hopefully a young QB prospect also from the draft to boot.
IMO Stefen Wisniewski would be a very under rated & overlooked, quality FA signing. I know he's had some difficulties that seem a bit uncharacteristic to his prior three seasons of play, but he is working with a rookie QB in the early phase of a rebuild.
Granted, Wisniewski isn't cut from the same mold as Pouncey, but he is still a very good young, smart, Center/Interior O-lineman in his own right, who can fill the position consistency, I believe. I think signing Wisniewski would have a lot of bang for it's buck like the Slauson signing had in the 2013 season.