Build a secure customer portal

Hi, I am in need of a portal website based on php. I need to distribute reports to my clients through a password protected website interface. I need my manager to be able to log in and select a client and add the report to a specific client's page. Each client will have multiple reports. Then I need to give my clients unique usernames and passwords to be able to log in and only see there reports. In addition to reports, I need a section of the portal to be able to broadcast general news and updates. This section would be the same for each clients page. So almost like a module that my manager could update on his dashboard. The manager would need to have an easy dashboard interface to add clients and be able to change their passwords and publish reports. What would you estimate that costing? Let me know if you need me to clarify anything.