I'd give a 4th for Williams. He would be a nice addition and push Ball out of the picture.
They probably want a 2nd or a 3rd...but, it won't happen.
They may also consider a player plus a draft pick. We have some guys on our team that could be expendable. Guys like Julius Thomas, Knowshon Moreno, or Andre Caldwell.
Or, how about Tracy Porter straight across for D. Williams?