framework - best framework to use for web application

I am building a web application that will help manage documents in any organization. Users will be able to upload files in pdf format and pass it to another user for evaluation etc. The receiver will get a notification that he has received a file etc.

I am unable to decide which framework to follow, so that it is easy to scale the application for many departments. For client side should I user Ember or Angular. Should I exchange data and update pages using ajax(using json) for better views or use just jsp for all the dynamic content.

I have done the basic coding and but now I have to scale the application for better user experience and more features. So I was thinking of using a framework.Is single page application type architecture good for this ?? Please help !!