Word Header issue

I have to create a Word template that is setup in a way that the first page header is one image and as soon as a second page is created (or text is inserted and auto creates second, third, etc page), a second "main header" is in place (smaller than the first, with margins auto adjusted). If this Word doc could also eventually be easily updated for other Word templates down the road that will keep the same concept: A front page header and a main header on all other pages.