Document Management

I have a customer who is a title/abstract company. They have an exisiting website and would like to add a "CLIENT" area to their site. Here's how it would work. The CLIENT would be issued a username/password to access this area. The title company would have an admin area where they could upload the title report (either as a .doc or .pdf) and assign it to the proper CLIENT to be viewed. The CLIENT would be able to login any time and be able to view ALL abstract reports that belong to them. CLIENTS would only be able to see their own reports. The admin of course would be able to see ALL abstract reports and/or search by user. Again, most importantly the title company needs a simple to use admin area where they could upload the reports and assign it to the proper client. This will be built on a UNIX server. SQL is available if necessary. Please let me know how long this would take and what programming languange you'd use to accomplish this task. (cgi,perl,php)