Add file upload system (gcpa)

I have existing website and I would like to add the following script to my site. User File Upload System: 1. users need to be able to create login id 2. users gets email confirm of account creation 3. users validate new account 4. users can upload and manage files 5. when user uploads new files, admin receives email notification 6. admin manages user accounts 7. admin uploads response files and user gets email about response file