Need gallery where the thumbnail is different from the enlarged picture

Does anyone know of a gallery plugin that allows you to have a thumbnail that’s different from the enlarged image? I am trying to list magazine covers that open to a page inside the magazine viewed in a lightbox.

Example: One of my pages in my site will show a bunch of magazine covers in a grid. When someone clicks on a magazine cover, a lightbox will pop up that will show one of the inside pages. The thumbnail image and the enlarged image are different images.

All the ones I have seen so far are ones where they are the same image. As this is for a client who isn’t too web-savvy, I hope there’s one out there that doesn’t require me to FTP the enlarged photos.