I've used Van Dyke's (http://www.vandykes.com/category/desk-leather). As you can see, there is quite a difference in price between their "house" hide which cannot be embossed and their custom leathers. Several years ago when I needed some leather, I ran across the name of an outfit in Ontario who sent me a swatch packet. Unfortunately, I can't recall the name and I can't find the samples, but I do believe that they were importers of Muirhead leather (http://www.muirheadusdirect.com/). They were not easy to get ahold of for a quote, so I ordered from Van Dyke's. As it turns out, Van Dyke's was just the middle man. They sent my patterns (required on odd shapes) elsewhere (Ontario?) to have the leather cut and embossed. It was expensive, but beautiful. I installed it with a synthetic wallpaper paste, following the directions found here http://antiquerestorers.com/LEATHERinstall.htm.
Have fun!