Online the grass cloth yoga mats run anywhere from $30.00- $80.00 the mats usually are 72" x 24" which creates a nice size panel. This company seemed to have some unusual ones http://www.shalincraft-india.com/furnishing/mats/yogamats/yogamats.html or you can try http://www.healthandyoga.com/html/product/yogagrassmats.html.
You will need an experienced Carpenter to add the molding around the mats and to hang the mats if they don't feel they can you hang the mats you will need an experienced paper hanger. The type of molding you add is endless choices but I think I would try for something simple. If you did not want to stay with the natural colors you could paint the mats to fit with your color scheme. (do a test on the mat to see how the paint reacts)
When you are done you have a great looking wall treatment that brings in great texture and nature into your room.