As for your expanded version, I think I would prefer Kosta Koufas coming in and Oliver Lafayette going out. I think with Rasheed's trade kicker (15%), it would work with Hollins coming in and either Koufas or Stiemsma going to GS. I think the Celtics need to think very carefully about their center options.
Perk will likely not return before February and it is legitimate to question whether he will be able to contribute next year at all. O'Neal is no spring chicken and has missed a lot of games due to injuries in the past. Garnett prefers not to bang inside and is under-weighted for such duty. Big Baby is game but very under-heighted for such duty. Erden is an iffy option, especially in the early part of the season. Picking up a 4th center, who may see lots of time, seems prudent but will have roster implications rippling down.