Amd, you of all people can definatly carve out your own lower! If you went with a 0% it would be CHEAP. The drill for the buffer is 1 1/8 and the tap is 1 3/16 x 16. The rest of the tools you probly already have. I don't think you'll save $ by building the upper, but some one may correct me on that one. You can get rifle kits for a good price. They come with all the parts but the lower.