While I can understand wanting to try to re-gear an existing bike, I am a bit confused about your requirement to stick with 700c wheels on a new bike. It seems to me that you are going to have a pretty hard time finding a frame that fits your height. Are you concerned about finding replacements on the road for the smaller size (650 or smaller) wheels?

The reason I ask is that I have 2 touring bikes. One has 700c wheels, and the other is a Bike Friday with 406 wheels. And both bikes have identical gearing. With the Bike Friday I don't have the luxury of walking into just any bike shop on my route and buying a replacement tire, but then again even with the 700c small bike shops often don't carry good touring tires. When I travel with the Bike Friday I often bring a spare tire with me. When I rode across the USA and decided to replace my tires mid-trip, I just called Bike Friday and had them ship new tires to me (on route).

Of course if it's a "I don't want to spend the money for a new bike right now" issue, that is definitely understandable. But if you are looking at a replacement touring bike, I would consider the smaller wheel size in order to get a frame that fits.

--- Denise