Hopefully if it does in fact land at UA/Amazon, they're willing to throw whatever budget Mann asks at it. Especially if they can snag most of the actors mentioned. Story itself seems like a pretty tricky proposition to put on screen, but hopefully they can pull it off.
Driver could do a solid Pacino impression. I could see Leo as the villain from the book (Wardell?). I guess butler could be young Val Kilmer? No idea who. Cooper plays.