Online Web-to-print Design Tool

I need an online web to print design tool to be integrated into an ecommerce platform. Currently I own SunShop with all of the source code. I am open to other suggestions if SunShop will not be a feasible platform, but it will need to be as robust. I would prefer the project be coded in HTML 5 and CSS3 and not be based in Flash, because I would like this to be functional on tablets. I will supply ALL graphics via layered Photoshop files. The site will be storyboarded with all functionality needed on the front end for the user via jpg files with comments attaching each one. The base code for the homepage design and a shell for subsequent pages (header/footer, H tags, text paragraph tags, etc.) with CSS has already been done. Some modifications to the shopping cart may need to be made to accommodate my needs, such as adding advanced search features, add-on products, etc. Once the customer has selected a template, uploaded appropriate photos, added text, and gone through the preview process and purchasing, the project will need to be saved within their account with a unique order number. A layered PDF at 300 DPI will be the desired output needed. Design tool is going to be for greeting cards, announcements, stationery, business cards, etc., so I will need to be able to create templates for various sizes and shapes. On the administrator side, I will need to be able to create these layered templates and select what can and cannot be edited by the front end user such as text, photos etc. I will also need to be able to select what fonts each template can use, colors available for the user to change. Most all templates will be 2 sided so that will be a key as well. The design tools needed to edit products will be the ability to change text, fonts, change font color,center left and right justify text, upload photo(s), rotate images, zoom images, enlarge/zoom images, change images to color, sepia, black and white. I am looking for a company to grow with. I want relevant portfolio examples of what I am looking to do as samples of your work. Some example sites are as follows: [login to view URL] [login to view URL] More examples if needed upon request. I am willing to pay by milestones: 30% at start 25% first live version 25% delivery of finished site (including installation/operation manual) 20% after bug fixes