Any industrial supplier should sell the clamps or just replacement jaws. Try MSC, Grainger, McMaster-Carr, ect. Personally I've had the best luck ordering from MSC (
www.mscdirect.com) and most of the time you get your order the next day. Grainger is strickly wholesale but I was told that if you order through thier website and with a credit card number they wouldn't know the difference.