I am 5'10" and 130lbs, yeah really skinny, and my mediums are perfect for me. They aren't baggy or skinny, they are correctly sized. I will try to find a picture if possible.
Ok. I might want it a little more on the baggy size. I'm thinking of large, since I'd want these for 2 seasons and I'm mostly likely going to grow more.
I have a large Saga fatigue, so I want it to look good with that. I feel like the fatigue is a slimmer fit so I don't want to end up with baggy pants and a slim jacket, although the jacket seems like it's not slim on me.
I couldn't find many good pictures, but in the 12/13 lookbook, on page 10 and 11, they look pretty similar to that on me. you could probably PM BloomOuterwear and ask what size would be good or Jim will probably post in this thread.
I would for sure get the large if you're looking for something that fits between baggy and slim. I am 5'10" and 140 pounds. The larges on me fit slightly tighter. Considering you're a couple inches shorter, I think they'll fit how you want them to.