Hi Chandu,
I have few queries on your question.
1) Do you want to view the DMS documents already stored in EP or just need a tool to collaborate documents with external business partners?
2) Is user license is a problem to you?
And kindly do not mix up content server with SAP DMS. SAP DMS can be used without content server also and content servers can also be used by other SAP applications without DMS.
Regards,
Ravi