DiMosaico - a good range of both stone and smalti and hammer and hardie sets. They also have filati for micro mosaics. www.dimosaico.com
His Glassworks - primarily to do with glass cutting but a great range of wet saws plus videos, http://www.hisglassworks.com/cart/cart.php?m=product_list&c=67
Mosaic Art Supply - a range of stone rods plus a lot of other resources to use.