Hi praveen let me clear about one thing,
are you going to develop a project for academic year?
or
Going to develop project for your client requirement?
coming to the point if you are going to develop a project for a acadamic year no need to worry yaar just try to keep the modules as per your knowledge after searching something on "online sales" you may get a lot of information for doing this project. even if you want some more information i will tell you regarding the modules for the acadamic purpose.
the very important to discuss over here is , if you are going to develop a project as per the client requirement than you have to decide what modules has to be developed as per the client requirements.
dont worry just gothrough the document of your reuirement definately you will get an idea.
So forst of all you just fix your requirement than you will self decide which item need to be seperated from other
and you will get how many module need to keep in the online sales project.
i hope this will help you.