Here's one that could realistically go down.
Ray Allen, J O'Neal, and Avery Bradley to the Bulls
CJ Watson, Ronnie Brewer, Omer Asik, and Kyle Korver to the C's
Bulls do this because a still have a serviceable backup Center in O'Neal, backup PG in Bradley, and pickup a better SG than Hamilton is. Ray and JO's salaries are off the books this year, and Avery is a young prospect but could be let go the following if he doesn't show enough to warrant picking up his deal.
Boston does this because it gives us a solid young Center prospect in Asik, a good SG in Brewer, and a solid backup for Rondo in Watson. Korver can sit outside and knock down the shot as well. None of them are signed past next season, so we will have the ability to keep flexible and not get saddled with bad contracts. We can see if Brewer, Watson, or Asik can be pieces to the puzzle.
We have to plan on the fact that we realistically are not going to get one of the big name free agents, so collecting a couple role players and trying to draft well is about all we have at this point!