f50fan, it's not about what he
needs; it's a "want some bling" thing.
Shortsocks, get whatever rocks your boat, either cog will work just fine. You'll need a shiny chain to go with it, and some good cranks. Better not have some crummy rattle can paint job or the effect will be lost and people will point and laugh at the poseur.
Unless you're going for that whole ironic thing.