We need a simple chooser with preview for the header images. The previews can be quite small. As there may be the option to choose another, much higher image for the start page this needs to be separated out.
So create two instances for the chooser: Front page image and image for the rest of the page. If the user does not want these two to be different, maybe we include a checkbox to set the two identical by default: If you check the box, the second image-chooser is activated.
Am not totally sure which should be default. One image and image height for all header images is a default behaviour, but having the bigger one for the front page more reflects joergsarts Design.
Will provide a little mockup (not for beauty, but for clarification)