Why pay money when you can do it yourself, like the pro's?
Just use rsync, it is the only method that will not break your busy servers while doing a backup.
What do you think they use when they do your backup? Heh...
Edit: Check what
bqinternet.com uses as procedure.
Features:
Daily backup using rsync technology
SSH encryption
On-the-fly compression
Get back online instantly with a Samba mount
FTP access
No data transfer limit
No setup fee