business card and postcard design online

I need a program to run on a linux server that allows a website visitor to design a business card and/or postcard online. The ability to upload and add there own images, background images, and be able to place font in the color and size of there choice anywhere they want on the document. Then be able to save the document on my server for possible ordering for print after it has been designed. This would most likely require them to sign in as a user. I am assuming this can be accomplished with a mySql data base and the program done in flash? That would be upto the coder.