Kwame would be a great pickup for 5 million or under. He is very underrated defender though he doesn't block shots. Instead he relies on quick feet and agility to stay behind his man. He similar defensively to Kurt Thomas though without that same mean streak obviously that makes Kurt Thomas so valuable (or used to make him so valuable).
He could put up near 10 and 10 for this team if he plays 29-32 minutes per game. He'll get left alone alot due to his stereotype of not being to finish strong which may or may not be true.
The one benefit to signing Kwame is that he maybe the most healthy since his days with the Wizards. He hasn't logged heavy minutes throughout his career and still is only 28 years old.
However, I would not give him enough money to be satisfied, because I think he has very little self motivation to be great. Rather, he would like to just fit and chip in and play his role which isn't necessarily a bad thing with this particular team.