Integration with R/3

Hi everyone,

I have a question regarding the integration between SAP R/3 (where data resides) and SAP Netweaver (where R/3 data should be pulled into):

1) Should I use MDM or will PI be sufficient? If MDM, what exactly is the added value?

2) Are ABAP Webservices sufficient to do the work or is it not recommended?

Regards,

Wesley.