http://portland.craigslist.org/mlt/bik/3084960174.html
There is also this one at 22 inches. I could always go into another bike shop and ask. I am not an experienced bike person so I don't know if I would immediately know if it is a good size. How tall are you?
There is also a non mixte motobecane:
http://portland.craigslist.org/mlt/bik/3150909258.html Is this one any more valuable? There dont appear to be safety lever brakes.