You could do a manual build, see my Yosemite guide link in my signature.
Did you use a kext utility to replace the kexts or you just manually copy and paste?
After replacing the kexts, did you repair permission and rebuild cache?
Here's how I got it to boot. Remove the 2 kexts, repair permission.
Use kextwizard to install the patched kexts, run repair again.