For iGPU you need GraphicsEnabler=Yes not no, also must be set to 64MB in BIOS, not 96MB.
In your boot.plist you also need to put the Graphics Mode option with your monitors native resolution for the iGPU to work.
Also are you running 10.8.2? there is a know issue with the 10.8.2 update and some z77 boards this board included. If so u need to be using the AppleAPCIPlatform.kext from 10.8.1. Do _NOT_ use a patched one that you downloaded from some site, just backup the one in 10.8.1 before you apply the update and replace it before you reboot. Avoid patched system kexts when at all possible.