I cannot take credit for the replica bannerstones. They were a gift from my wife. E-bay is the likely source. I do however, know some of the rock types used historically. Banded slate, quartz, pudding stone, and many types of igneous rock. If you want to research them further I recommend the books
Atlatls and Bannerstones: Excavations at Indian Knoll by William S. Webb. and
Bannerstones of the North American Indian by Byron Knoblock. Both are published by Gustavs Library. He has a website to that effect. The first book has a great section on atlatl hooks, handles and bannerstones. This is the definitive work to explain placement of bannerstones in context. The other book shows every conceivable bannerstone in North America. You may be surprised by the craftsmanship the early natives possessed. I was amazed. To my knowledge bannerstones are only found in North America and winged bannerstones are only found in the eastern US.
Another good source is the website
http://www.primitive.org/atlweights.htm They have an article on there for bannerstone classification and function. Fascinating stuff. Everything above is sufficient detail for replica projects.
Some of the winged bannerstones were crafted with pecking and sanding. Hard rocks were used to peck away a bit at a time. Then some sanding with sand stone and a leather/grit slurry that polished things up good. The holes were made with cane shafts and flint dust as an abrasive. I have heard of estimates of 200+ hours to craft one of these bad boys using traditional methods.
Another book that has a short section on bannerstone construction (a darned good reference for other native American Prehistoric skills too) is
Sun Circles and Human Hands: The Southeastern Indians - Art and Industry by Emma Lila Fundaburk and Mary Douglass Foreman. This is an old book printed in 1957 but I have seen some recent paperback reprints in select gift shops. I betcha a flint arrowhead Amazon.com or B&N has it online.
Sorry to be so windy. I just love sharing this stuff. Enjoy the references and if you end up making your own bannerstone please post so we can brag on ya.