I've heard it's easier to adjust a too-small bike to fit than a too-large one. I don't know if I believe that. I'm the same height (last weeks dr. visit had me a little shorter, too!) and I've always ridden a 58 cm or 23 in, but I've gone up to 59/60 cm bikes. I'd rather spread out a little more than feel cramped.

Short of a fitting, you could go to some bike shops and try different bikes. Along the way you'll get some input on what size fits best.