But now I just feel disproportionately short. I"m just shy of 5'1" in my bare feet, and I'm on a 43cm bike. I tried out a 47cm WSD, but I have to stand on the very tips of my toes in order to clear the top tube. I'm guessing that's not such a good idea (even though I wish I could "graduate" to the 700c wheels!).

Or, do you feel that the "reach" is more important than clearance?