I think terrys have the shortest top tubes, especially if you consider that they also have the slackest seat tubes, so they definitely have the shortest reach. I even think Gerogena is running a sale on the symetry http://www.terrybicycles.com/detail.html?item_no=3019 which I did notice is available in a 17.5" which I would guess to be your size. I also think if you order it from terry directly, they will ship it to your bike shop and have a 30 day return policy (although you may be obliged for the shipping charges, talk to them about this if you are interested). Also ask their advice on sizing. It even comes in a 16".