I stuck to tonys CustoMac Buyer's Guide an bought the GA-Z77-DS3H with an 3,4 GHz i5, 16 GB of RAM, 256 GB SSD OCZ and the GeForce GTX 660 TI with 2 GB.
The first time, I booted and installed ML via USB from Unibeast everything worked fine. But after installing Bootloader and Drivers from Multibeast, the OS X didn't come up again. (Stopped after "iobluetoothhcicontroller start completed")
I checked several posts for BIOS configuration and installing without the dedicated graphics, but none of it got my CustoMac working :(
I reinstalled now over 10 times, but booting didn't worked. (Stops after "ACPI SMD failed to locate SMC driver").
I'm using Z77-DS3H board with i3 CPU and GT 640 GPU and EVERYTHING works for me, EXCEPT: After installation of ML 10.8, I run MultiBeast to install Chimera and from then onwards it just won't boot from hard drive, I'll get the Chimera Boot screen (press enter to boot Darwin blah...) but when it tries to boot ML it gets stuck.
Yet if I use the USB UniBeast Boot and select Mountain Lion on the hard drive it boots fine without any flags or arguments.