I'm guessing you're not a coder? Therefore, a script with a database included is for you. And as it's for a site that sells something, you're looking for a 'shop' script.
How proffessional does this have to be? A lot of people first starting out tend to use CafePress as the engine behind their site and modify the html to gain the look of the main website. That way, cafepress handle the printing and orders.
You haven't given a lot of information really
