Hi Ambikes, I just put up a post on my Rocky Mountain Sherpa. I am considerably taller than you. I have the 50cm. I see that the 47cm is the smallest Sherpa size. If you read anything of people who owned the Sherpa, most bought a size smaller than their normal road bikes. If you have the patience, here is a forum thread on the Sherpa that may help:
http://www.bikeforums.net/showthread...ghlight=Sherpa

I tried a 53cm Jamis Aurora and I was a bit too stretched out on it. The smaller size brought the head tube far too low for me. I already struggled with the 53cm. The Sherpa fits me very comfortably. I have short fingers and have no problems with the brakes/brifters. I even like the sloping top tube.

I think the Sherpa 47cm has a 520 length top tube. How is that length for you in general? Check out the height of the headtube and see if you can try a comparable bike for size. Include mtn bikes too.