Honestly think that short term(next year) and long term(keeping salary down for 2012 and beyond) that the perfect addition would be Grant Hill.
First off, signing Hill to a two year LLE of about $2.1 million per means you don't have to bring back Green and can sign and trade him. Hill gives you so much more than Green ever could. Salary cap flexibility, passing, consist defense, consistent outside shooting and a veteran's presence with the second unit all for millions and years less on a contract. He can also play either the 2 or 3.
He leaves the MLE to be used for a center or PF with length, he leaves the sign and trad option open on Green which could net a very nice future option whether it be a first round pick or a possible young player to develop.
Redd is a veteran's min player due to his injury and could probably be added as well instead of Von Wafer.
But if it came down to Hill or Prince I want Hill, age be danged. He brings so much more to the table, has been healthier of the last three years, is familiar with Doc Rivers and is one of the true nice guys who you never have to worry about in the locker room.
I would then try to package Davis and Green in sign and trades and use the MLE on one year contracts for Leon Powe and Kurt Thomas and go with the philosophy of:
"If everything works out and everyone stays healthy we have a championship club, if not and Thomas, Powe, Redd, and Hill turn out to be too old and/or injured, well, run as far as you can with what you have, clear the decks for 2012 and go for the Chris Paul for Rondo trade and do everything to land Howard."