Well, first of all, we can't really get rid of Sheed's money, and Scal is coming off the books, so lets take that part off the table.
As for the guys you mentioned, they are all very valuable players at this point. I would say, short of giving up someone like Perk, you wouldn't get your hands on anyone like that, other than Barnes (who is no better than Daniels...in fact, he is worse), or Pietrus (who has become very mediocre this season, and looks like he has lost about 20 pounds...right when Rashard Lewis gets nailed for PED's, hmmmm). Guys like Ariza, Lee, and Gibson are all late picks who have panned out. They are not guys who will just be given away. And Blatche is looking like a star in the making...if they give him up, it will be either for a star, or to get rid of Arenas.
Now, more realistically, I think they could look at guys like Travis Outlaw, Amir Johnson, or maybe throw some cash at JJ Redick. They also could go after Mike Miller with the MLE, or a sign and trade.
The other thing they can do is trade Perkins. Then they could possibly get a Courtney Lee or Taj Gibson, as well as another asset...but it may not be enough to make it worth giving up Perk.
More likely though, they need to hope Danny can use his late picks and find his own Lee, Gibson, or Ariza. He has had plenty of success drafting that late before, and maybe he can have it again. But I certainly wouldn't count on anyone being a rotation player next year.