Digital Download – hide the file path

I’m trying to offer up a free-trial download of my company’s software product after a registration form is filled and submitted. The trick is we need to guard the file path to keep it from showing up on Forums, Blogs, offshore, etc.

So far I haven’t had any luck via Gravity Forms and various other ‘download manager’ type plugins to make this happen. The basic steps we are looking for-

1) send the users form information via email to us AND
2) serve up the file for the visitor to download AND
3) give them some sort of note “thank you, we received your info” or drop them on a thank you page url.

Again we can’t just use a confirmation page with a URL link to download the file because we do not want the (file location) link visible or to be able to be copied and distributed anywhere for direct access to it without registering. Unless that link were unique per visitor or would time out after so many hours/days. Hidden would be better.

Very open to suggestions at this point. The file type is a “.msi” and some plugins won’t support that I’ve learned.