Check out http://signaturecycles.com/document/111627
They are excellent bike fitters. You don't have to purchase a bike from them and they can help you figure out what type of bike would be best for your needs.

Level Two Fit

The Level Two Fit is for determining what Custom or Stock frame fits you best by using the Serotta Sizecycle. It will ultimately determine the sizes and locations of all your components as they relate to fit and performance. It is a 2-2.5 hour process that starts with the Level One Fit system. The Serotta Sizecycle is an infinitely adjustable bicycle fitting tool that will allow you to experience an unlimited range of bicycle fits that will assist us in determining your proper frame and component measurements. The Sizecycle will provide us with the critical target coordinates that we then manipulate with proprietary frame geometry software that will give us your perfect frame geometry and component measurements for a custom bike. We then can input the data of any of your stock manufacturers’ frame choices and determine what frame size and component options would work best to come closest to your perfect fit coordinates.

In doing this, Signature Cycles provides a valuable service to those who are buying a stock frame.

By assuring that correct frame and components are purchased at the outset, the fitting fee itself is typically recouped immediately. That is to say that by buying the closest to "perfect fit" stock frame along with the appropriate corrective components, you will not have to repurchase the same components later in order to bring the parameters of the bicycle fit within acceptable limits. Such necessary secondary purchases can easily be a large percentage of your bicycle's original purchase price.

Elements addressed during the fitting are: correct length crank arm, seatpost, and seat; the length and degree of stem along with the correct number of spacers. Care is also given to the correct handlebar reach and width. Without a considered and formal fitting procedure these elements are never adequately addressed by "off the shelf" bicycle purchases.