There is another option, that being getting a Surly frame and building a fixed around the "Steamroller" it's a great frame, and made for fixed gear.
Myself, I like getting old stuff and working with it. All my fixies have been old, found on a trash pile, bikes. They are old clunky steel, but when you take the weight off of them, deraillures, brakes, freewheels, you get a very cool bike. Steel is such a nice ride. I do have an old Cannondale Al frame, it's fun, but boy does it vibrate.
If you are looking at fixing and old bike look for ones with horizontal rear drops, rather than the vertical kind. With the horizontal you can utalize a flip/flop hub and run a taller gear on one side, or run a freewheel on one side, in case you want to laze back home. I prefer running like a 16 on one side and a 20 on the other, that way I can go smaller if I gett too tired for the big gear, or encounter wind or weather.