If you want a genuine American style sheepskin coat. Not the more refined designer type but the real McCoy, then this Pat Garret guy sells quality items. He knows sizes too so they can consult you if you take some measurements on a proper fit with say a heavy sweater on.
I actually had him design me one at a premium and he did a very good job. The coat is warm and impermeable. I used a more distressed skin than youd normally find.
http://www.sheepcoat.com/