Web to Print Add On

Does anyone have a solution or add on suggestion for web-to-print? I have been using Zen Cart for years and don't want to abandon it, but we have a wide format printer that we need customers to be able to upload images and design a product on our website before we receive the order.

Can you clarify what feature(s) are being sought?

What seems clear is, a file is uploaded by the customer (after some level of editing). Is it the act of editing that is being sought? Or is it something about the print side?

If the editing, I would like to think that there is some javascript/jquery editing tool available to allow the customer to do something with the image. Not saying that such features wouldn't be commercial but I know I've seen others post in the forum some sort of solution/concept that worked. Otherwise, if the image has already been edited, it just needs to be uploaded it seems...

Well, one is that we will be allowing people to upload and place images for canvas prints and yard signs. Another is that we manufacture diplomas and custom home school diplomas. We have several options for them, but we can never show them a mock up until the order is submitted, create a pdf and email them a sample. It would be nice for them to be able to design it on the screen so that they can see what it looks like before placing the order.