Magento Custom Static Block

We need a static block designed for Magento that will be placed on a category page which will list all of the "series" (subcategories) associated to that category if the category has series (subcategories) OR products if the category does not have series (subcategories). The products or series (subcategory need to appear in a table layout with one product or subcategory per row. If the category has subcategories the grid should list the subcategories and the attributes of the products in the subcategory as ranges. If the category does not have subcategories the grid should list the products and their attributes. When a subcategory is selected the same grid should be displayed with all the products of that subcategory and their attributes.