I'm not too experienced with the i boot -> Retail DVD install method, but can you boot in Verbose mode (-v)? I always go with a myHack USB installer, even for 10.6, go with that for the Chameleon bootloader, makes things easier IMO.
So.... An AHCI-related kernel panic... That's the kernel, you can't use the stock mach_kernel it looks like... Unless... Try booting with the flags "cpus=1", "-v", and what the hell "-f", -f never hurts lol... No quotes when you enter those flags...Again, not sure if you even can with the disk setup.
What is your EXACT motherboard and CPU, is the CPU C2D?