Client information plugin (or similar) needed

I’m developing a site for a TV Antenna installer who would like a ‘client login’ area where they can access the status of their order, see where they are up to in the workflow of the job, and add questions or comments.

This would have to enable the client ‘user’ to only view their own job details, progress and have the ability to ask questions and receive answers by being nitified by email of any change in their job’s status (which could be triggered by the post being changed or a comment being added. I can see that a normal ‘post’ would do the job if I can restrict access of a logged in user to only one post. AND i’d rather not be setting up individual categories and sub categories for each user as this needs to be user friendly for the company i’m developing the site for.

Are there any plugins that do this? Are there any plugins that handle this sort of client interaction? I have searched for a few hours and no one has a complete answer.