Hello list

I'm looking at ebXML viability for adoption as a messaging standard in a health sector.  I have some questions, in particular with ebXML-MS messaging, where we have some requirements I need to be assured can be met.

• For small sized participants in the sector, peer to peer messaging (non-hub based) is required. Am I correct that ebXML-MS v3 supports this and version 2 does not?
• What is the minimum ebXML component set that needs to be deployed for a minimal ebXML-MS based messaging solution? i.e. is the registry mandated? The context here is we simply don't need CPA's etc in the first instance - just reliable messaging (we may grow into a fully collaborative pattern later).
• Within a messaging community, for small sized participants, what is the minimum technical commitment for message post in terms of ebXML-MS.  The context here is we undertake a lot of collections, some Web form based, some B2B where in the past we have provided a lightweight client for third party systems integration.  In terms of fulfilling this under ebXML, can the client commitment be reasonably lightweight?
• If there is knowledge in this forum on HL7, is the v3 Web Services option and v3 ebXML option interoperable?

Thanks, Len