Header change each category page?

You can do that manually, and I have been doing this as well, I don’t know if there is a shorter way, but this is what I do.

First of all, collect the category IDs of the categories that you want to have a different header.

Then create a file category-*id*.php

Copy everything what’s inside the usual category.php to the category-*id*.php of yours.

Delete the line that calls the usual header.php and open up header.php, place everything that’s inside the header.php on top of the category-*id*.php that you made and customize at will..

I know it sounds complex, but well, it works for me.

Also see Template Hierarchy and Category Templates.