question about module in application

Hi, I've been asked to develop an application with two modules, an online store for selling digital books and the other module is a special page where my client wants to post poems and let the users put comments on the publications. This page must look like facebook's news feed. I think the closest thing similar to this is a forum. 

I don't know if I should include another application into my application or write the code myself. Your comments are appreciated.