There is no such speeds available except possibly to backbone providers. The fastest fiber internet I found was 200MB http://www.skyriver.net/services/enterprise-broadband

You did not list your country, budget, or anything, so do a web seach of your area providers, what you can get will vary greatly by where you are.

What exactly do you do to "need" such a huge internet speed? Nothing except a specially set up point to point connection will transfer at such speeds over a WAN (universities, research labs, etc..).