Giuliani may be a liberals RINO, but he'd be good in this post. 1) It would be personal. 2) He's really good at law enforcement issues, his cockeyed 2nd amendment stance aside.
It is also a huge bureaucratic reorganization, needful of an extremely aggressive corporate executive COO type, of which Ridge may have more the Guliani, but I doubt either has enough to pull this off.
I could see Ridge in a Cabinet Head post, with a deputy (TBD) extremely strong in organizational skills implementing Ridges/Bush's policy.