There's a few ways of doing this. You can either set a custom template set for the category (edit the category and enter the template set name in the Category_Template field), or you can edit the detailed.html template and put if statements in there.
If you want to use a different detailed page per category, then the first method will probably work better for you. You'll want to create a new template set directory, and create a .tplinfo file to make your new template set inherit from the luna (or your current) template set:
Code:
{
inheritance => '../luna'
}
Then in that directory, add your custom detailed.html template.
Adrian