looking for a Gamecube controller to ps3 converter

I'm bringing my CMVS to a con to run some tournaments. Seeing NG game have been ported to the virtual console. I like to give the attendee option on what they want to use in term of controls. I have the standard db15 for the neo cd controller and joystick. Undamned encoder for ps3/xbox360 controller and fightstick. Does anyone know of a good product that is still in production to convert the GC controller to usb(ps3) to be use on the undamned encoder?