e-commerce Web front end for php+postgresql based inventory management system

I have already created the database and pages for managing inventory input and order processing, Just need customer facing "pretty" inventory browsing and credit card processing pages to interface with database back-end. This server is housed internally and sites based on wix, or wordpress are not an option. I would prefer only html css and php be used in this. Any abstraction tools like; cake, netbeans and the like are also off the board. I am ok with code igniter but i want to be able to maintain updates in the event that you may not be available in the future.