I don't see the Bills using a high draft pick on a WR in next year's draft. The WR room is deep on this team. The top 4 WRs are under contract next year. I could see the Bills trying to get a speed WR later in the draft.
I could see high draft picks at OT (both Williams and Nysekhe are FAs), LB (Milano is FA), CB (Norman FA), or DE (Murphy FA). They may try to bring some of these back but doubt Norman and Murphy are coming back.