Custom Design Generator

I am the owner of a custom vinyl decal company. I need a script for customers to create custom decals online and make purchases of their designs with my Mal-cart. Customers need to be able to input sizes, colors, text, effects and images which will then create an image and get the price. Price will be determined by the Size, font, color and effects chosen. The script should have the ability for the user to upload their own fonts or use fonts from a library from within the site. The background color should also be selectable for the preview. The ability to bring in images from my online catalog and add text around them would be another addition to the generator. Examples can be seen here: [login to view URL] [login to view URL] [login to view URL]