Not so sure I would go with larger than what you have. The Medium Crosstrail is a 17.5" frame, my DS8.3 is also a 17.5" frame. Both the DS and Crosstrails have similar frame geometries. My height is just a smidgen over 5'9", at 155 lbs, a little lighter than you but basically the same height.
I had test ridden the 19" DS (same as the Crosstrail large) and found it to be too long.

Here is what my DS looks like, setup for my height: