I tested iMac14,2 SMBIOS, and it also works at 60Hz.
But I think it would better to use Macmini6,2 SMBIOS since it works at 60Hz and the AppleGraphicsControl.kext does not contain a block for Macmini board ID's, so we can just install Yosemite and use Macmini definition without having to edit the kext.