If you want a more direct and exact image you can use dd and netcat. It would be best if you could take the servers offline for a period while you do this operation. If that's not an option, you can still do this, but you will need to run fsck after you are done. See this article for more information:
I would suggest that you create a virtualbox VM with a disk 2% larger than the box you are trying to capture. this virtualbox Vm will serve as the "target system" described in the article. Set this Vm's networking mode to bridged so it has it's own IP on your network. Boot this VM from an ISO, my personal favorite is "Trinity Rescue Kit 3.4". Open a port on your router pointing at the vm so that the VPS can connect.
If you have any further questions, let me know!
Regards, Port Forward Podcast