Beyond what you'll fit into, the question of what type of fit you prefer is tough to answer. To provide another point of reference; I'm 5'10", 185lbs, slightly biased towards long torso/short legs...both the medium and large fit me fine, but differently. When I first went to buy Assos, I couldn't decide which fit I liked better from trying them on at the shop, so I ended up buying one pair medium and one large. With some miles on them, I discovered that the large pair "disappeared" more, which is what I prefer. The mediums are still in the rotation, and still plenty comfy, just a different fit.

Based on that experience and your dimensions, I'd venture a guess that you're going to be better off in the smalls.