Product listing headings between

Hi Everyone,

On some of my products I use the product listing page only as a place for people to add the products to the cart, So a big list of products is shown and customers add the product from the listing page, as seen here:
http://kitchenwarehouseltd.com/complete-kitchen-units/high-gloss/cream

What I am hoping to achieve is some way of splitting this listing up at a defined point and adding a header, So for example I could have a header of "Base Units" and have 10-20 products under this heading. Ideally I would like the products to be styles so they can be put in an accordion style. This seems like it will take a little bit of custom code but is there anyone who would be able to point me in the right direction, or anyone that could suggest a better idea of how I would be able to get the same effect?

Thanks,
Daniel