Completely different theme based on product category

Hi,

I have been working on this website and my client asked me to create a seasonal campaign on which a totally different theme will be shown (besides the header and the footer) for products of specific categories.

What I need, is not a template for the category page. That would change only the main category, but the product page, cart and checkout would be the same. What I need is that, maybe using some programming, when the user is navigating a sepecific category, or products within the category, all the products related pages (I have which ones specified) will use a different template for visual behaviors.

The easiest (and poorest) way would be to create a different wordpress installation for this specific campaign only, but the client want the control panel and all configurations to be the same, and syncronized.

Any hints on how would I be able to archieve this? Any advice is welcome, thanks!

The page I need help with: [log in to see the link]