I would trade Sullinger and Amir for Noah any day!
I stille believe that Noah's got what it takes, but right now Bulls are not playing him enough.
I Believe that Noah would be a better fit for our system than both Sullinger and Amir, who I don't believe in as building blocks in Brad Stevens system. Noah is not a long time solution either, but would be a small upgrade until we find our superstar center.
That's because you don't watch the NBA and you're thinking of Noah from 3 years ago. That much is exceptionally obvious from your post. The current incarnation of Noah is a role player off the bench and nothing more.
For instance, we have to assume you haven't seen Amir playing 26 mpg and having one of the better +/- stats on the team? Nor witnessed his good defense - good enough for the Cs to be 3rd in the league on defense. Nor remembered that he has a non-guaranteed $12m contract for next year making him an exceptionally flexible trade component both this year and next.
You may not realize that Sullinger's status as an RFA makes him easy for the Cs to retain (if they wish) or to perform a sign-and-trade since RFAs almost never move teams in the NBA. Or you may have not seen Sully pulling down about 9 boards per game and playing acceptable defense. Or how his contract and status make him also a decent trade asset.
Perhaps you may not realize that Noah's shooting percentage has declined for 6 straight years (to a Rondo-like eFG of .383). Or you must have not noticed how Noah has become a massive liability on the offensive end - something the offensively-challenged Cs don't need. Then there's Noah's expiring contract, which makes giving up any even remotely decent assets counterproductive since he's not putting this team in the NBA finals this year and he's a UFA at the end of this season.
In short, there's not one decent reason to acquire Joakim Noah at this stage of his career. He offers almost nothing to the Celtics. The best case he might get the team two more wins (not even a playoff series) before he's a UFA. The worst-case you make the team worse now AND lose better long-term tradable assets.
Frankly, none of these guys have any real roles for the Cs. Gasol could help the Cs win a playoff series this year but the guy is 35 and is going to opt out of his contract. A reasonable argument could be made for getting him in a "temporary rental" scenario but the Cs are probably better off hoarding their assets for more of a long-term approach. Besides, Gasol probably has more value to another contender who might be willing to pay more for that rental.
Noah? Just...no. Offers nothing this year and nothing long term.
Gibson? The Cs don't need another Brandon Bass. Gibson offers very little short term or long term to the team. Amir is already on the team and a better fit. Depth isn't a problem and that's what Gibson offers.