I want to have categories with a different layout than usual

I'm working with this template:

http://bit.ly/cigw6M

And my client has asked me about making a couple of categories look like this with the table layout for all the different sizes of a particular product:

http://snipurl.com/1gpgef

How would I go about doing this?

Thanks in advance.

To do this with the product listing page, each size would need to be a separate product, under a generic product subcategory.
The example has a couple of fields that do not exist for standard Zen Cart products; you may need to create a new product type (following the example of Product-Music), or you may be able to repurpose some unused fields like weight.

The price area could best be done with the Flexible Product Listing mod (in post 50 of a forum thread here - search for it), as the standard listing does not have enough identifiers to control the price elements.

This will take a good bit of work for any method. The actual method will depend on exactly what elements/fields you need to display. The example uses javascript for the part no. and stock popups, and this would have to be custom coded.

Sounds like a lot of hard work. I might just pass on it. :D