just like to say a big thanks! to all the advice on these boards, I finally got to the installer and currently says time remaining only 6 minutes! Pretty happy so far.
So to confirm I'm using
MSI X58 Pro-e (Latest Bios 8F, 19/03/2011)
Gigabyte Nvidia GTX 560 1GB
4GB DDR 3 Ram (recommended in a video somewhere to have no more than 4GB...)
only one HDD installed, only one video card installed, no other devices connected other than USB stick with Unibeast installed.
Using Unibeast 1.5.3 and latest Mountain Lion from the App Store.
I had the constant restarting problem after 'Starting Darwin' and 'Boot Args', no matter what arguments I put!
But the brilliant advice here helped a lot!
Like: Set the Drive to AHCI (in this board's bios go to RAID and change from IDE to AHCI)
and to go to CPU Features and enable Execute Bit Support (also in the bios).
Of course you also need to set to boot from USB, and with this board the USB option doesn't come up in the Boot Options in the bios unless you have the USB stick plugged in when you boot up.
Lastly, to get this far, I did need to enter the argument PCIRootUID=0, since I'm using nvidia card.
Anyway, still installing, so I'll post again when I've gotten further.