I don't see the Brewers adding a bat as I think they are contempt with what they have in their young players to fill any holes that may come up.
Pitching wise I think the Brewers will try and add a starter to replace Lauer if possible. Someone like Wheeler, Giolito or Lynn I believe will be a target. The Brewers did try and get Carlos Rodon last year from the Giants so I think another starter is probably going to be what they go after.
Bullpen is probably the other spot as usual that the Brewers will try and fill.