The Bulls supporting cast isn't that great: Noah is a lot like Varejao, Mo Williams and Luol Deng are probably equivalent. Carlos Boozer would be the trump card, I guess, but we've seen him in the playoffs...
Deng and Mo Williams are absolutely not even close to equivalent. Mo Williams is a streaky shooter. That's it. Deng can hit the mid range jumper, slash, do the little things, and is a great defender.
And Boozer's career playoff numbers are 20/12 on 50% shooting so I'm not sure what you're getting at there.
The big question to me is this: what does Pat Riley do next off-season? Even with a MLE the only decent centers are Nene, Tyson Chandler and Samuel Dalembert. It is really unlikely that they could persuade any of them to take a pay-cut. So would Riley be ready to break up the trio via a trade? Because Mike Miller, Joel Anthony, Dexter Pittman and a 2nd isn't exactly a spectacular offer.
I would trade Wade, personally. I think he is the most replaceable in terms of position (shooting guard who doesn't shoot), fit (no synergy with LeBron) and age (a very old 29). The odds of that are slim to none though; but both Bill Simmons and Dan Le Batard mentioned Wade first in the hypothetical.