The late great Darwyn Cooke would have been a shoe-in, so I'd go with Lee Weeks as artist with maybe someone like Warren Ellis as writer.
I'm not sure about that. Cops are only supposed to kill in self defense, and are rigorously investigated when a fatal shooting occurs. The Shadow mows people down with twin guns while laughing maniacally like The Joker. Would Batman admire The Punisher? Did Batman admire The Reaper? I can see Batman begrudgingly working with these guys and respecting their abilities, even if he finds their methods abhorrent.