On the most recent show I downloaded, they agreed that "champing" and "chomping" at the bit were both okay, but I have also heard "chafing at the bit." Isn't that one all right too?
"Chafing at the bit" is okay, but it doesn't mean the same thing as "chomping/champing at the bit." "Chafing at the bit" tends to mean that someone is feeling restrained or hampered *and* is interested in going full speed ahead. "Chomping/champing" at the bit just means that someone is impatient *and* wants to proceed.