Most of the 1st gen B20A parts can be cros referenced to the 2nd gen B20A or the A20A. However, some of them are totally specific to this particular engine. It might be a problem for those that buy these engines and are looking for an easy way to buy those parts.
I will try to post a list of stores that I know will ship worldwide. If you know of a store, just post it there and I will update the list.
Here it goes:
http://www.bgautomotive.co.uk/: Head Gaskets