Using Sharepoint as Virtual Data Room (VDR)

Thanks Dean_Gross for your response.  Indeed, I am intending to set up a separate site collection away from our main site, making the security and control abit more manageable.

Our VDR will contain several projects within, and we will only allow limited access to the external parties the project they are interested in. It is easy to share document externally, but the control feature in Sharepoint is very lacking. It is manageable for now when the number of users is just a few, but when the number grows, control features, like auto expiry, users management tool and content management tool, will be very helpful.