Interspire Shopping Cart Programming

I have several small projects for an Interspire developer. **MUST KNOW INTERSPIRE SHOPPING CART 5.5 ** #1. Create a copy of each physical product as a downloadable product using a CSV file I will provide. This should be able to be achieved with a relatively simple PHP script. #2. Develop a way to link physical and downloadable products back and forth (preferably automated- there are over 1000 products each with physical and download versions) #3. Created an option for physical products that adds $10 to the price- this must be able to be enabled or disabled from the product administration on a per product basis. Can you help me get this customizations and database population down quickly with robust code? THANK YOU SO MUCH!! ## Deliverables I am open to alternative solutions to the issues I've raised. The project needs to be done quickly and accurately. What I really need is there to be modifications to interspire to allow my client to sell AudioBooks in physical and download formats. Because of the way interspire works we either need to have desperate download and physical products OR modify the system to allow both downloads and physical products in one product variation set. If there are separate products (one physical + one download per audiobook) then the site navigation needs to make sure that there aren't 2 copies of each product. Let me know if this needs any extra clarification.