Hi
1. I think you have to upgrade because this IS-Oil is add-on module. it is not part of ERP 6
EHP7.
2. If your are planning to integrate to any other SAP module(like SAP BI,Portal) with ERP 6 EHP7 system. just read the SAP Note before starting the installation.
1388258 - Version Interoperability within the SAP Business Suite
BR
SS