Hi Rebella,
just FYI, there is now also a reference integration available for SAP CRM. For details, please refer to https://wiki.hybris.com/display/release5/SAP+CRM+Back-End+Integration and Note 2293490. The package is based on 5.7 and may help you by giving a starting point (although it does not include PI as a mandatory component).
Regards, KArsten