Extending Categories - to make them page like.

I have created a number of Custom Post Types ((Releases, Articles, Interviews) which all use my default categories.

I'd like the Category Archive permalink to link to a page that displays all of these, which is fairly straightforward, but I'd also like this to be a page or like a page so that I can use the Page editor to add content before the posts/CPT's are listed.

I understand that I could make a page template that would show content and then all the category loops below it, but it wouldn't be at the Category Permalink.

So specifically the Category Archive would display a Producer and then there'd be a bio etc entered via the Editor and then CPT's E.g. Releases, articles etc listed below.

What's the best way to do this?