They should let you test ride anything in the store without anything more than taking a copy of your driver's license. They should also help you choose the correct frame size and do a fit and setup on whatever bike you buy. That's just standard service. Some shops have all kinds of super duper fit equipment that may or may not be helpful. Either way, they should be able to do a traditional fit pretty easily and get you close to where you need to be. In fact, they should even offer to let you come back after a month or so and redo the fit if necessary. Most LBS are smart enough to realize that every time you return to the store for a free service like a fit, that you are likely to make a purchase....