That does not ring any bells for me.  Doesn't mean it never existed, but does mean that it must have been pretty obscure if it did.

There were issues putting G4 upgrades into the 6-slot PPC Macs (except the S900) which had problems with PCI cards in teh lower three slots.  There's some kind of Bandit arbitration bug on the second Bandit when a G4 is installed.  NewerTech or maybe PowerLogix found a solution to this, and then the solution found its way to Sonnet by way of hired engineers.