Would your EFI (BIOS) be properly configured with proper variables and associated "stuff"?
I'd be tempted to install (from the install disk) your OS and tell it to set up GRUB properly, as an EFI boot.
You could then adjust any partitions and run rsync over the top of it.
Note that you would probably have to mess with the UUID's in GRUB because they would be changed and run update-grub.
Also you would need to adjust your fstab.
Would doing all this be necessary or don't I understand EFI?