Custom header gallery for each page

I am building a site for a client. They have seen a friends WP site and that friend has a different gallery in the header of each page. When they add a new page, beneath the edit area, there is a list of fields where you can add the images which you want in the header of that page’s gallery. Of course, this is what my client wants.

I didn’t think this would be a problem but I can’t find a plug-in which does this and can’t figure out how to edit an existing plug-in to do this. Has anyone got any ideas?