Custom Tshirt designer website

This can be hosted on either win/linux or whatever platform. We are looking for an applet very similar to [login to view URL] However, we also want to make some changes and would require the system bbackend of what [login to view URL] consists of. Immediate plan of action is to purchase a design applet that allows customers to create a design from a template or by the use of the design tools. Customer must be able to do just about everything [login to view URL] allows the customer to do. I.E. that is for the customer to be able to change the colors in each graphic. Graphics can be SVG if need be, but must be able to be exported as AI or EPS files for printing and seperations. Also, would need a backend to keep track of orders and update status for customers.