Lee is a double double guy night in and night out that plays out of position. You can pay Lee 10 mill a year for four or five years and he'd likely be happy with that. Or you can pay Bosh 18-20 Mill a year to do the same thing.
Personally I'd sign Lee and try to get a single free agent (LeBron, Kobe, Wade or Joe Johnson).
Gallinari is an anomaly. He clearly has the ability to score 28 points in a game but he is completely inconsistent. If Gallo could score like this game in and game out, the dynamics would change. We wouldn't be talking about getting a free agent to get us into the playoffs, we'd be talking about championship runs. That's really how important Galinari's success really is to the Knicks.
Think about a consistent Gallo, a healthy Tmac, Lee being Lee and a free agent of your picking. We'd be were the Magic are now in terms of wins and respect.