Yes I did,a few years back. 
Tv show is still in development.right?
Fantastic book. IMO the Twin peaks (since it's mysteries are still largely intact) and The wire of comics.
I'd recommend anything by Azzarello and Risso. Spaceman, the 100Bullets spin off Brother Lono as well as the ongoing Werewolf/hillbilly horror book Moonshine

It's been announced several times. Several parties have been interested. Problem is that someone starts shooting people now and then in America, and the premise of such show becomes a tough sell. Even if it quite clearly isn't in favor of gun violence.