Have you tried downloading the patched installer again - I just wonder if something has gone wrong in the download that is causing a problem at install. The version I downloaded was hosted on Mega and linked from on P1 of this thread. I don't think the RAM speed will be a problem as I understand it it will just run at the max speed it can (667MHz) but this isn't based on first hand experience. I have the same SMC version but upgraded the CPUs on mine and applied the firmware update but the previous Boot ROM was MP11.005CB08 which I think I updated when prompted by Apple many years ago. If redownloading doesn't work have you another Mac to use to install using Target Disk mode using Yosemite from Apple and then change the efi files as described earlier? Or perhaps you have already tried that. Or go straight to El Capitan - I am in the middle of doing that now and had it running nicely last night.