Protected Client Area for Review/Download/Communication

[John Locke]

Anyone know of a CGI or PHP program that does the following?

I've been setting up my new site to include a login box for clients that, upon logging in, will take them to their specially made Client Review page for them to see samples of media or download files related to ongoing projects for them. So far, I'm doing this with a CGI password program, by making their page by hand and manually uploading the files by FTP, and then by tracking communications through my separate e-mail program.

I'm wondering though, if there is some software that already exists out there for this. I see these "Client Login" areas all the time on design, photo, and production company sites, so there must be something tailor-made for the creative fields.

What I'm looking for are these features:

1. Standard password and ID assignment with auto mailing upon creation. Multiple protected areas possible. Only one, embedded login box is necessary, with clients being directed to the proper protected area by their ID and password.
2. A threaded forum to allow communication back and forth with the client and have it on record. The forum would be just for that client.
3. A download area and preview area.
4. A backend admin area that allows creating protected areas on the fly through templates, register clients, and upload files.

P.S. I'm looking specifically for software designed for creative professionals providing special areas for their clients. I'm trying to avoid having to manipulate time-intensive programs like Web-App, etc.