First thing I would do is update your profile with all your Hack's components so we can see what you have!
OK, if the "fix" has caused the loop then boot into your UniBeast usb stick and do not choose your main hard disk. Boot as far as the installer screen but don't go any further, instead look to the menu bar, choose Tools and in the drop-down run Terminal. From there you can use Linux/Unix commands to copy your backed-up config.plist back over the modified one in your EFI folder.
If you are not familiar with the Linux commands for List, Copy, Delete (ls, cp, rm) etc then look-up their usage - I have a book but Google will help too. The hardest part is getting the destination directory correct - such as: /Volumes/EFI/EFI/CLOVER
Type: "diskutil list" to get a list of the disks attached to your machine and their partitions. Find your main hard drive and write down the disk identifier of the EFI partition. e.g disk0s1 or disk0s2 etc.
You will then need to "mount" the volume EFI partition to begin the repair. If memory serves me correctly the Terminal commands are:
mkdir /Volumes/EFI
sudo mount_msdos /dev/disk?s? /Volumes/EFI
... will probably do it. (replace ? with the correct digits from diskutil) Please double check though! You should then be able to "list" the partition and see the EFI folder.
You don't say where the back-up is. If it is on the main hard drive then just copy it from its location over the one in the EFI/CLOVER folder.
Sounds complicated but if you can't boot any more it is worth getting to know the commands.
Unless someone else reading this can offer a better method?
