Where are you going to find cap room to sign a max player when you've added 19M in salary to the books for this offseason?
You would have to amnesty Pierce.
If we were to get Josh Smith I think the trade would look similar to the deal you proposed
To Boston: Josh Smith, Marvin Williams (if they are trading smith they are going to shed Marvin's contract).
To LAC: Ray Allen
To ATL: Bledsoe, JO, Foye, Gomes, a first from us a first from LAC (2014). We probably would have to throw in Bradley or JJJ as well.
This trade is unlikely unless Atlanta decides they want to shed salary desperately.