WebSphere applications and SAP R/3

Hi all,

my customer has WebSphere and wishes that one develop a specific application for human resources in connection with SAP R/3.

Which would be the best architecture of development for this application? And especially which are the tools which I must have?

Moreover, I recently Web Services in NET connected to SAP, can I developed re-use them for this application?

Thanks for your help.

Regards

Eric C.