shipping only when option is selected

Hi there,
Is the following possible? I tried every combination of shipping but can't get it to work:

I have a product (online video), so no shipping required. So far so good, everything works.
This product has an product-option that people can select which is a collectors box. When this box is checked, i want to have two options visible during checkout: Eshop_item & Eshop free. (free means collect at shop, item means sending via analog mail.) 
When i set the send option in the product option to 'yes' nothing happens, also not in combination with other settings.

Hope to hear from you!
Regards, Martin