Products sorted by attribute price & displayed on product listing

I am developing a mattress website for a customer using Zencart and they need the ability to have categories for not only the brand, but also to shop by size, and comfort level. I know that I could make a separate listing for each, but that would compound the number of products unnecessarily. I know that there is also the search and filter functions of various addons, but what I want to achieve is similar to this website: http://www.mattress.com
As an example when you would like to shop by size, and click "twin" it shows the listing for each mattress that has twin as a size and also shows the price as well.

Here is the site I am working on: http://www.mattressconnection.net
I have been trying to figure out a way to do this as part of the drop down menu and not as a 'search' function. Perhaps I am missing something??? Any insight would be great.

I would seek to clone the manufacturers module and use it for the vertical browsing options.

~Melanie