This is the first sword they've done and I have to say they did an awesome job with it. They worked with Mr. Martin for about 6 months to get it right. Needle (Arya's sword) is being done next, and that one will be high carbon steel. Longclaw is stainless because of the etchings to give it the Valyrian steel look, and no sharpening option because it looked odd combined with the etched pattern. After Needle, they will be releasing Eddard's sword "Ice" which should be awesome considering the size of it.
You can get it directly from them
here and I believe through a few other resellers.