Pooks-
I think you should call the Jamis people directly, explain your situation, and ask them for their suggestions about how you can test ride an Aurora and figure out your proper size frame in person. They may surprise you and make some cool arrangements, or have some info unknown to you about where to try them. I would think they would want to do everything possible to get you test riding their Aurora, as opposed to bike shops which (naturally) want to sell the stock they already have on the floor. Make the phone call- it can only help!