You might try Bulltetproof Primitive Suppy. Madison Parker, who owns it makes really great slingshots. He operates out of Florida and is a really nice guy. I was looking into a slingshot before I decided to go with a .625 caliber blowgun. His website is down right now http://www.bulletproofprimitivesupply.com/

I have his card with his contact information, but its at home right now. At this year's SHOT show, I read they had a slingshot with a laser sight on it, known as the LaserShot. Trust me, Madison Parker's rigs are much more primitive.