i am 5 feet, 9 and 1/3 inches tall without shoes. 32 and 1/3 inches cycling inseam without shoes. i'm chosing between 15.5" and 17.5". i care for ergonomic fit and not racer's posture. perfect fit is very important for me. sadly its tougher to fit me since i'm out of shape at 218 lbs (hopefully new bike will change that ). your advice will be greatly appreciated. thanks.