I too have short legs and a long torso. I have a 49cm Lemond Reno and it's been great for me.

Previously, I had a "crunched" feeling between my shoulders when I rode SilverSon's 50cm Trek Pilot for any distance.

The LBS really pondered the recommendation, but concluded that I needed the shorter vertical height and extended horizontal distance. I've not regretted the decision one bit.