As others mentioned, you need to find to which SAP product you’re migrating exactly.
SAP works very well with EDI, actually. You will still need some EDI translator / middleware. Your experience with EDI will be quite valuable for the migration project. Some books to consider on this subject:
They can always use Corman, Lispworks, or Allegro, I presume, if they're not going "all in". For class or experimentation, that might be what they're looking for.
[Going off on a tangent, there seems to be a new Emacs book on the market.]
I'm currently studying Windows Communication Foundation which is used for Service-Oriented Architecture (SOA). I will be reading Windows Communication Foundation 4 Step by Step but I've already gotten started by following a few tutorials. Today I tried out WfcStorm which does performance load testing of WCF services.
Combined with Entity Framework, Windows Communication Foundation seems to be the current Microsoft technology for enterprise solutions.