Most of that I had book marked before were not worth using, most likely why I never ordered any. I do see that http://www.clanart.net has several in pewter that can come with a nickel finish. I have heard that http://www.custom-celtic.com can do custom work, as should most people who make custom jewelry.

Also, if you do not mind doing some design work there is https://www.shapeways.com/ who can 3D print and have the finished products in silver. For more information on the silver: https://www.shapeways.com/materials/silver