In the following picture (desired layout)
the grayed area is reserved for the header. It is supposed to be fancy looking with tikz pictures, chapter/section names with pretty fonts etc. The outlined area is where the main text will fit.
t denote margin lengths against the A4 paper edges.
Although I'm confident :-) I can design the header the way I want, I have no idea on how I can achieve the desired layout (especially the thing that the main text has to indent differently in the "header area" than in the rest of the page).
I'd like to use this layout with the
article classes, but it would be nice if I could also use it with the