Code a basic email collection form with secure download link

We need something similar to the way this link works:
http://dl.nin.com/theslip/signup

the process goes like this:
1. Person enters in email address into a form
2. An email is sent to that email address
3. The email contains a brief message and a unique link to a file to download (this needs to be secure)
4. The emails will need to be stored securely and accessible via ftp in a text file separated and ready to use for batch email services like mailchimp etc...

We have web space and a basic server available but just need help in coding this. Ideally this will need to be live by the end of October.

No design is required but the code will need to be available to integrate into a basic splash page.

Any questions just give us a shout :)
Si