Here's what I know
I know that there is an ISO cert on the OBD II standard. Unfortunetly you have to pay a fee to get the correct interface information. The numbers are ISO9141-2 / SAE J1962 Now the interface is a standard RS-232 connector, which can be bought from most electrnics/computer parts suppliers. If you e-mail me so that I know you are interested, I can provide some more info and sources for you.
Phillip