Modify existing digital (only) shopping cart

I have an existing website that has a digital download shopping cart that allows payments with paypal. I would like you to customize the current setup on the Admin side to allow for tangible goods to be sold and include shipping. The front end will need to be customized also to reflect the addition of tangible goods and the shipping. Your work must be themed to my current setup (front end and back end). If you have installed the Canada Post API on other sites and can include to this project this is a plus. The current set up is purchased from codecanyon.net. To view the module please see below: [login to view URL] Thank you for viewing.