We are sure you had the idea in your head. To buy an old bicycle, or just the frameset, and build a fixie/single-speed with the parts of your choice. Good news! Our friends from Global Cycling Network just did it. They bought a really cheap Peugeot classic bicycle and turned it into a single-speed perfect for commuting with style.
Sit down, take your notes, start looking for the perfect frameset on the second hand market and come to Santafixie for the components.