Good, I was afraid you were looking only at WSD bikes. You know what I do once I know what top tube length I want? I get on the web at look at the geometry/measurements of any bike that is in my chosen price range/performance critieria. You can then even estimate if the next size smaller might work - just be careful that you don't sacrifice headtube height and can't keep the drop from saddle to bar to a reasonable number.

It sounds like you've got enough data to do this. VeloNews and Bicycling just came out with their annual reports. You might find some bikes listed there that are worth checking the measurements. At your height, you have a wealth of bikes from which to choose (lucky you!), you just need to find the brands with the short top tubes.

Good luck! Don't let that pro-oriented shop intimidate you. You sound far beyond what I would call a recreational rider, more of a "fitness" rider but not a racer. Recreational to me is someone who hangs their helmet on the bars and doesn't have their brakes connected most of the time. Your money is worth the same as the next person's and you're the one standing in their shop. A good fitting can save you lots of time - - just be clear on the type of riding you want to do.