USB Connectors or their supported Headsets are not normally found in Aircraft to my knowledge.
You will have to try and obtain a proper certified Aviation Headset to be honest? If finances don't stretch that far you can find secondhand ones on the usual online sales sites. Be careful that you select the actual one you need though as many sellers don't know what they I have I notice and often mis identify them on sale.
Otherwise you won't go wrong buying a new A20 - they are unbelievably good and with the later Bluetooth, connect to most portable devices too.