Problem Types for specific departments only.

We really would like to be able to have problem types by specific departments in our team. For example, if we select problem type 1 to be Accounts then I would like only the people who are involved with accounts to see these. It would be nice to be able to have private problem types so the director could see ALL problem types across the company but he could have a problem type called 'director' which only the director and maybe upper management have access to. We utilise out supplier and customers on prospects for everything, it would be nice to have all of our tasks company wide being able to be managed within prospect, rather than having to keep another confidential list elsewhere outside of prospect.