Somebody coming from the documentary side of things - Alex Gibney would be my pick - in order to 'nail' the grime and feel without resorting to lazy 70% f-bomb script dialogue and using pastiche from other, better directors, which is essentially Tarantino's calling card. Caveat: I think Michael Mann could pull it off though.

Why Tarantino? I'd expect him to pay homage to some obscure filmmaker more than I'd expect him to bend a fairytale back towards reality.

I'd go with a showrunner from "Justified" and yell at them not to make up too much of the mayhem. The "bad guys" on that show ring true to me, they are self serving, nihilistic and make poor decisions.

It's interesting how life imitates art.