I've been playing with the banner boxes on a dummy version of my site, and decided they could be really useful if I could figure out how to show items from a particular category in them.

To explain a bit:
I have a shop on Etsy, and they provide a little app called "Etsy Mini". It's just a javascript that can be placed on a blog or website and shows a few items from my Etsy store.

You can see an example of "Etsy Mini" inside a banner box on the left side of a dummy version of my Zen Cart here:
http://gorgeousbuttons.com/dummy/index.php?main_page=

Now.... What I'd like to do....

Is set up a specific product category -say "Independence Day Items" and link to it with a javascript similar to the Etsy Mini app, so it shows a few links directly to a rotating list of products in the specified category. This way, I could set up different banner boxes with different active dates, and link them to different categories for holidays, special occasions, birthday gift ideas, etc. The only ongoing work I'd have to do would be to link each product into the categories, and let the automated banner box handle it from there.

How hard would this be to accomplish?