Sani-chips are virtually dust free so are nice for burrowing snakes that go down in them. They also absorb urine better. I like them b/c I have an issue with airborne dust. But b/c they are smaller there could be more of a problem with potentially swallowing some with the prey. There are debates over whether this is a valid concern or not. I've heard it both ways.
Finding it depends on where you live. Some suppliers sell it at retail outlets, just depend what the pet supplier carries in the store.
What are you housing in it?