"and he can move in with me when I do,"
Why? What's the rush?Why not see what he does, how long he can stay sober? He can go to the Salvation Army, free program. Rehab does not make for recovery, it is all about what he does AFTER he gets out, can he manage to stay sober without a structured program? That is the real test.
You have a no contact order, there was a reason for it, rehab will not change his personality, who he really is.