Crashplan you could also do a peer to peer at a computer setup offsite just for that purpose.
I'm thinking more of the initial upload, 8TB is probably many many years worth of work, with my plan I get 500GB transfer, that's 1.3 years to upload
I guess you could get Shaw's Unlimited 250 which has 15Mbps upload and test their unlimited fine print, you could do 8TB in what, a couple of months? Lol...