I am redesigning a website that at one point was attempted to be done in magento. This site specifically sells online tests that are simply a HTTPS html document that you fill out online content, hit submit and the information is sent via a form mailer. In magento, this functionality did work. You could create a product to sell, go into the file download and either specify a manual file to have the customer download, such as a pdf or alternatively a URL web link to send the customer in their invoice. When this product was purchased, they could click a link in their email that would generate a unique encrypted link to this document that was stored on a 3rd party server and it opened fine.
We are trying to port this same functionality to drupal as it's a much easier CMS form and things seem to work better. However, the core functionality for their downloadable products doesn't work at all with ubercart. Ubercart from what i can see will only allow us to upload specific files that the customer has to download. We don't want them downloading these html files. We simply want them clicking a link in their email, it opening the URL to this document on a 3rd party server in their browser and going from there. I haven't seen any other modules that can duplicate the magento download URL functionality either.
Any ideas from anyone of any modules I could use that will allow selling file downloads via a URL external that links to a 3rd party web server, without having to upload any files?
By the way, I have so far looked at ubercart, commerce and ecommerce. I thought I saw what I wanted in filefield sources but not sure on that yet.