How to change gallery page layout per page?

I'm wanting to know if it's possible to change the layout of a gallery page on just one page. My current style is set to Packed. I'd like one page in an index to be set to Slideshow. I had a solution from the previous forums but it wasn't a full solution. A code infection for my page header would be amazing if anyone has any leads?

I am also wondering this! Have you found a solution?