Jason,
If the shortest possible length is your primary concern, go with the 54". If a little more smoothness is most important to you, go with the 56". Ron LaClair has shot these bows a lot more than about any of the rest of us, so I expect he knows better than any of us what works well. I know he prefers the 56" bow for himself. I do think that the foam core bow will be about as smooth at 54" as the actionboo core bow is at 56", so that could be a good tradeoff. Since you have awhile to wait before you get the Shrew you ordered, think about it. In the meantime, I will go out and shoot both length Classic Hunters side by side on several occasions and will then give you a better analysis of what I think would be better for you on your first Shrew. I do definitely think you ought to get the Classic Hunter with the foam core, carbon backed limbs and with a Bow Bolt. Obviously, the woods and overlays are a matter of personal preference, but think about what you think would look best from your point of view. Gregg does beautiful work, so whatever you pick he will turn it into a work of art.
Allan