Free Download Product with registration?

Hello,

Trying to find a way to be able to have free downloadable products and paid downloadable products. Most if not all of our products are downloadable but we also want to provide a good bit of free ones as well. When adding a free product we seem to still have or show the "Add to Cart" button we would like to remove that and have it show "Download" instead? Is this possible to eaisly do or would we need some major modifications?

I think it would be great when setting a price for a downloadable item that you should be given the option if you want to give it away as a free download and then this would in return change the add to cart to a "Download" button for people to download the item. it would also be great to have them still have to register to the store this way you can still market to them for all of your payware items that you have and other things.

Would anyone be able to help me with this?

Thanks,
2Wayne