Design Modification of a PHP dynamic storefront script

Our storefront script is written in PHP and it is populated by data received from the Amazon associates store feed. This script is about 10k lines, neatly written and easy to understand. The goal is to improve the design of the script. Model the general image of the website after pixmania.com. This means that the boxes, search bar and items should become rounded edged with a slide shadow. The items displayed should have a round border. The boxes are: searchbar, categories, subcategories, mini cart, cart and any custom boxes. In general all the pages in the site must be consistent in style.