Marketpress setup with different shipping options when selecting different pricing

I am selling books in different formats, so each product has a price for print format, a price for digital format, and a price for print+digital combo. This is different pricing configurations under the same product item. How can I make it so when they select digital, it does not include Shipping, and when selecting the others it will include shipping. Secondly, when selecting the digital price, I need it to auto send the download link when that happens.