All joking aside, all those bikes are much too big. You need a 54cm. Everyone has a langster right now, and they feel small and nimble. They are aluminum, so they are a rough ride, but light. That Bianchi is a conversion, which isn't technically a "fixie" but a road bike with a fixed rear wheel conversion. You'd have better luck going to an lbs if you are interested in bikes of that price range.