There are three books that deal with Confederate Sharpshooters. The latest one is Shock Troops of the Confederacy by Fred Ray. Another good one is Lee's Sharpshooters by Major W.S. Dunlop. Also a book by and about Barry Benson who was a Sharpshooter but I can't remember the title.

The badges are mentioned in Fred Ray's book. They were specific to the Sharpshooter Battalions and made of cloth.