For Spike: Zachary Levi from Chuck (Although Keanu Reeves prolly won't be terrible)
Jet: Jeff Bridges from Iron Man
Faye: This chick would would work if you wanted go low budget (she'd have to dye her hair, but she has nice breasts and the right haircut/facial features)
or Angelina for star power.
otherwise i'd say Jaime King
Everyone else I could give two shits about. Except Vicious i guess, he needs to be a young Jason Isaacs.
I love Cowboy Bebop, but I'm vaguely hopeful for this, if it actually comes out, because it would translate well to the screen without a ton of chop-shopping.
It's much more story-driven than most animes, as well as being fairly grounded, so it wouldn't need to be a super-cgi glitzfest. If you get the cast interaction right it would do well as a movie imo.
