Now I'm uploading my EFI partition to dropbox and send it to your email.
Unzip it, go to: EFI ▸ CLOVER ▸ ACPI ▸ patched, you will find there my dsdt.aml with injected properties of my 2 amd card, you must adapt these properties for your nvidia card, use this forum to do this!
In EFI ▸ CLOVER you will find config.plist with smbios of iMac13.2, I think it is ok and ready to use with your system! Smbios of iMac13.2 is the most apropriate for our system with nvidia 680m card!
Oh yeh, after install and before boot to Yosemite, copy and delete AppleIntelCPUPowerManagement.kext from Extensions folder because with it on first boot you'll get kernel panik. Once deleted this kext repair permitions with KextUtility of Extensions folder. After first boot you may install this kext with KextUtility. When you do operations on Extensions folder ALWAYS repair permitions with KextUtility.
I'll send you all my kexts, you can install them together with AppleIntelCPUPowerManagement.kext using KextUtility.
For you invidia card(s) you must use nvidia web drivers AND use boot argument nvda_drv=1. You can insert it manualy on every boot or insert in Boot section of config.plist.
Add your hardware in your sig!
And please, use search function on forum to find answers for your questions, all the questions are already answered!