If I was going to get a player by the deadline, it would be Suh from Detroit. I know the budget would have to fit him in and a new contract would be required, but he is the single dominant player that would change our run and pass defense more than pretty much any other guy. We need defensive interior penetration that just isn't happening to a great enough or consistent degree. If we had it our DE's would be having far greater success getting pressure and sacks, not to mention his own numbers. He is gone after the season, so Detroit might be willing to do the deal.
You have to remember that he grew up in Oregon and loves the Hawks. Could a somewhat home team discount be possible especially since he can see the championship potential for several more years?
I know it's a long shot, but there are not many truly dominant 3tech's that come available.