Data mining - download 18 million webpages sourcecode

I need to download 18 million webpages from one website. Provider can save the source code in html or txt. One file per webpage. The hard part of this project is the volume. I tried downloading using internet download manager and other downloading tool and the website will become 403 if it senses over usage and using proxy is slow. I can provide the 18 million web urls in txt, sql, or whatever of you choosing. Once completed, you may compress the files and upload it to an FTP account which I will provide to you. Time of delivery is the key so provider must have previous experience in past projects alike to show that you are capable of delivering.