Coupon Creator

I need a web application that would allow users to quickly create a coupon on my site http://couponslave.com. The coupon needs to then be posted directly on my site and also give the user the option to download it. As an example please see [login to view URL] The coupon would need to be standard size with a dotted outline but the user should be able to customize background color or image, font, and text. I am currently using a directory system that accepts jpeg and gif so the finished coupon needs to be in one of those formats.