your install is almost identical to mine... except i have a hd6450 not a 5xxx. The only kext i needed was IOPCIFamily.kext from 10.8.5 as the one in mavericks panics on this machine at the moment.
I have attached the file I used, plus a DSDT which i found elsewhere on the forum (Sorry I am not sure who originally posted this, but it is their work not mine) with these 2 files i got through install, (using myhack) I then had to boot using -f flag to copy the kext into s/l/e then it has booted fine ever since, and most things appear to be fixed in the DSDT, sleep etc... I'm running bios A22.
p.s. if anyone else is using these files, I have the optiplex 755 SFF