Custom Apparel Module Needed

I have a web site to sell embroidered apparel. I need a module where the user can either use text to add something to their item or upload a logo, then be able to view the item online. I am using Zen Cart and there will be several prices for embroidery etc, so the module needs to not only set it up from the customer side but also needs to determine the cost of the embroidery. The module will need the standard fonts, font size, italic, underline, bold etc. The customer-facing side of this needs to be very, very easy to use and needs to be compatible across MSIE, Mozilla, Safari and other mainstream browsers. I envision this as a pop-up window that opens when they click on "Customize" or something of the sort. In this pop-up window they will do the customization and the price will be shown as they add and subtract elements to their design. Once they are done, they will click "Complete" and the details will then be added to their cart and shown as a line item on their order. I am open to suggestions about this but I have a fairly clear image of how I want it to work. You will need to set up a copy of Zen Cart to use while making this module. My site is live and I would like to limit down time to only installation.