The Wiki entry says the Neo Geo Pocket Color version was released in the US. I don't believe it ever got it's own boxed release and had to have been released as part of those system bundles like Faselei! was. I had to track down an EU release so I could have the box for it.
I'd consider myself a fan of the series. I have most of the games that were released with the exceptions being the PS1 Cotton 100% port, the PS2 Pachinko game, Cotton Boomerang on Saturn, and of course the arcade originals.
Can't say that I'm aware of any PSP, PSN, or VC releases for the games. The Wiki article didn't seem to indicate anything at least.
http://en.wikipedia.org/wiki/Cotton_%28video_game%29