I'm only five feet tall and I have a 42cm Surly Crosscheck that I got at Alfred E. Bike. I think you can get the complete bike for around 600. What's nice is you can run fat tires on it and its steel so you can run it on dirt roads and you can put skinny tires on it and ride the roads. It gives you a bit of diversity. I love mine. I don't think I'd buy a kids bike, they just aren't built as well in my opinion. Then if you love road riding you can move up to a more expensive machine later.