I've never found a definitive voice for Captain Snow. The closest I've come is the singer Richard Cheese, famous for doing lounge parodies of rap/rock. http://www.youtube.com/watch?v=Mr7EBuz-2xI Snow's voice would probably be a little bit more gravelly. Mr. Cheese's cover of 'Stronger' is probably a better example, I won't post a direct link to it here because of the profanity.
If Archipelago were a musical, Snow would stop and sing this right about now. Or any time he wanted.