Hi David,
I went through the presentation available in Connect and I think it explains how Sourcing Request works in integration to SAP ECC, while I'd love to find out how does it work without the integration. Can you share any materials regarding such a solution? Answering to your question in the first post I'd like to add that I'd be much interested in participating in any meetings on this subject, though I'm not sure if it's not too late already?
BR
Pawel