You can use vanilla AppleATAFamily.kext and AppleIntelPIIX kexts, just set your ide channels to compatible rather than enhanced mode, I have the same panic when not in compatible mode. Downside is I can't see all my SATA drives, upside I can use OS X SL 10.6.2 which seemingly runs better then windows anyways.

Edit:
Also there is no need to do the mpkg method, the only mod I did to my install disk was that I switched it for the MBR compatible mpkg as I do not use a GUID partition map.