Home Depot sells two types of sink clips which can be used on channel type mounting. I don't know if they would work for your install, but you could take a look at them, return if they don't work. They are usually on a "Chip Clip" in the sink asile.

Hope that helps,

Dan Martyn

Your regular old neighborhood hardware store carries some stuff, too. Advantage is that it's easy to take the sink and try to match up the hardware.