Judy Mathison's book has detailed instructions on how to draft your own MC in any size you wish. You could draft your own and make your own templates
http://www.amazon.com/gp/product/157...RAPQH38GK3SYDC
However, unless you are hand piecing, I agree with the previous posters to foundation piece it in some way. The above mentioned book features a method using freezer paper where you sew next to the folded paper instead of through it. I loved it and made a beautiful MC quilt using Judy's methods and book.