Downloadable Product As An "option"

Hi there - long time no speak!

I am on 4.3 - If I want to add downloadable product as an option not just for the entire product, ie maybe send them a DVD instead - How do I do that?



The only way is to create two separate products and display link to the downloadable version on the product details page

We sell software and offer our users an option to get a backup CD disc. For the user information collection, if the user is NOT ordering the CD, I only want to collect their name and email, NOT their billing or shipping address.

If they are ordering the CD, I will need their shipping addres.

How do I set this up?