Post Editor Templates (how would you implement this?)

I have a client who is going to be posting different types of news within one news category. The website is very graphic-focused, and each post is written to conform to a certain layout depending on the content of the post (new products have a certain layout; competitions have another layout; media announcements have another layout, etc.)

Ideally I would like, within the Posts section, to have ‘Add new Product’, ‘Add new Competition’, ‘Add new Media Announcement’. Upon clicking one of those buttons, the post editor is loaded with text boxes relevant to how the content will be displayed in the post.

I realise I could use shortcodes that return HTML so that the layout is displayed correctly – but that isn’t a very nice way of interacting with the post editor for a client, and it can look very messy and become difficult to edit when things begin to float in the post editor.

So, how would you implement this functionality – multiple rich text editors and and optional post fields displaying depending on a post layout type an editor has selected?