I am in the process of creating an offsite backup, and need to do a initial load of data. Currently, that's about 400Gb, give or take 10Gb or so... The backup system is producing files which are about 4Gb each, and has some other, smaller related files also. So, i need to transfer all 400ish gigs to a remote server, but how? What is the best method?

I have full remote access to the server, so i can install anything i need to install. There are Windows, Linux and a Solaris VM running on the box itself, so any of those can be used there, and i have Windows and Linux at home. I have 2 internet connections in house, 10Mb/s uploading on each, so something that could potentially split the number of connections would be handy (kind of like GetRight, but in reverse... PutRight?).