If you're going to be commuting, go the road bike route. The skinnier tires will make you hate life a lot less and get you to work in about half the time/sweat loss. Plus, you get the chance to creep people out by wearing spandex into your office. I'd agree that a name brand is the way to go. Try craigslist...most importantly, get a frame that fits. With a name bike, the worst case scenario is that you resell it in 2 months for about the same price you paid (assuming you buy a decent used bike off cl).