Atlanta is definitely a team that could potentially have the players/assets to make a deal work, but I really don't like a duo of Young/Williamson for them.
Depending on where the knicks pick ends up this summer, I think they'd be the most likely destination if Zion is moved this summer. Something like Toppin, Quickley, Reddish, salary filler (if needed), and then 4 1st's i.e. 22, 24, 26, 28 for Zion and Graham. The 22 pick may have to be top 4 for New Orleans, but that would start to approach the value I think it would take for New Orleans to even be interested.