In theory, you go by the torso, so by that theory. you would not want a 57, since that would probably be closer to a person of your height who has the "normal" sized torso, which is to say a reach of 5'11", though possibly that is your reach if your arms are real long. I am 6'1" with a reach of 6'4". I should be 56 cm seat tube, and 60cm top tube. Custom maybe or the Nashbar frame which I understand is long in the top tube, though that is more or less a rumour. I just finished up a tour on a 58, and it was fine, though I probably needed a longer stem than I had. And a lower standover as on a Surly would have been easier to get onto. The satndard 58 I had was real nice to ride though.