Plugin/hack for creating a "filterable" grid but not involving posts?

Hi there,

I’m looking for a way to create a page which is a grid with each unit of this grid consisting of an image with short description. And for each of these units to be assigned a category/tag type thing which would then make it possible to filter this grid, sort by category, e.g. only show units in grid tagged with ‘X”. Each unit of this grid would also be linking to an external page.

I guess it’s basically trying to use WordPress a little as a CMS.

I’ve seen some plugins which seem to get nearly there with this – e.g. http://wordpress.org/plugins/grid-products/ or http://wordpress.org/support/topic/fyi-how-to-make-a-catalogue-grid-for-products-using-wordpress-as-a-cms?replies=7 – but the only problem is they want each unit to be represented by a post, and then subsequently each unit on the grid links through to this post. But I don’t want this. I just simply want an image with description field, both of which link to an external page’s URL which I can give (and for there to be this filtering option).

Does anyone know of any plugin which might be able to help with this?

Or any pointers towards how I’d go about making it myself? Either from scratch or hacking one of these existing plugins (e.g. “Grid Products” http://wordpress.org/plugins/grid-products/)

Thanks so much for any help you can give!