Hey Chandrasekar, I am not sure I entirely sure I follow all of your question, so allow me to cover as many bases as I can.
General RequirementsQuick Start Guide that covers how to add dSources
But, as to how much disk space and specifically how much cpu and compute you will actually need to support all the sources, you will need to engage your Delphix Architect as there are several pieces of information that we must collect and then run computations on in order to properly size your environment. If you don't know who that is, send me an email and I will track them down for you.