Here's the guide. It's not overly beginner friendly but it does work.
Required:
USB DVD Drive
Boot132 CD found inside the linked zip file
Mac OS X Snow Leopard Retail Install DVD
A second machine with a network share
Chameleon Bootloader binaries found here...
Chameleon Bootloader Binaries
The Snow Leopard 10.6.2 Combo Update
Kextutility found inside the linked zip file
Zip file found here...
ZIP FILE!!
I *think* this guide assumes some prior knowledge of installing OS X on a PC and for that I'm sorry. I have basically documented my methodology. As I've been out of the loop for a while I don't know if there's an easier way. Be assured though, this way will work. That said, if you already have a working install I'm guessing your main issues will be audio and VDA. In that case, if you update to 10.6.4 with the attached 'mach_kernel_atom' and use both the DSDT.aml and 'ALC662.kext' you should be just dandy.
Firstly, in the BIOS you need to enable 'AHCI' mode for the onboard SATA controller.
Secondly, you need to disable both 'Intel XD Bit' and 'Hyper Threading Technology'.
Burn the boot132 iso to a blank CD.
Restart with the DVD drive attached with the boot132 disc inserted. Press F12 when booting to enable the boot menu and select the DVD drive.
Once the bootloader has loaded, remove the boot132 disc, insert the Snow Leopard DVD and press F5 (I had to press it twice) to rescan the drive. Once it's successfully detected the Snow Leopard disc, type '-v' and hit 'enter'.
This should load the install DVD without any problems. Once booted, from 'Utilities' select 'Disk Utility'.
Select your hard drive on the right hand side and select 'Partition' from the list.
From the drop down menu select '1 Partition' and select the options button.
From the available options select 'GUID Partition Table'.
Select 'OK'.
Select 'Apply'.
This should partition your disc to be detectable by the installer.
Quit the Disk Utility and return to the installer. Follow the instructions to install the OS. It will take a good 45-60 minutes and you may get an error at the end saying it's failed. It hasn't.
Once it's finished installing, restart the computer. This may require holding down the power button to turn it off.
You need to put the boot132 disc back in and boot from it again since there's no bootloader currently installed. Once loaded, select your hard drive, type '-v' and hit enter.
Please bare in mind that from now on, if there's a problem with the installation of the bootloader to the internal hard drive you can still boot into the OS using the boot132 cd.
This should boot into Snow Leopard, it may take a while since it's the initial boot. Once booted, follow the instructions to set up your account.
Once at the desktop, open up the network share and drag the chameleon bootloader binaries and files attached to this post to your desktop.
Open up a terminal window.
Type 'sudo -s', hit enter and type your user account password.
Type 'diskutil eraseVolume "HFS+" "EFI" /dev/disk0s1' and hit enter.
Type 'cd ' (there's a space after the cd), then drag the i386 folder from the chameleon binaries into the terminal window and press enter.
Type './fdisk -f boot0 -u -y /dev/rdisk0' and hit enter.
Type 'dd if=boot1h of=/dev/rdisk0s1' and hit enter.
Type 'mkdir /Volumes/EFI' and hit enter.
Type 'mount_hfs /dev/disk0s1 /Volumes/EFI' and hit enter.
This should have mounted your EFI partition.
Type './fdisk -e /dev/rdisk0' and hit enter.
Type 'f 1' and hit enter.
Type 'w' and hit enter.
Type 'y' and hit enter.
Type 'q' and hit enter.
Navigate to the EFI partition in finder and drag 'boot' and the 'Extra' folder supplied with this post into it.
Back to the terminal window.
Type 'chown 0:0 /Volumes/EFI/Extra' and hit enter.
Type 'chown 0:0 /Volumes/EFI/Extra/Extensions' and hit enter.
Type 'chown 0:0 /Volumes/EFI/Extra/Extensions.mkext' and hit enter.
Type 'umount -f /Volumes/EFI' and hit enter.
Type 'rm -rf /Volumes/EFI' and hit enter.
That's everything done with the EFI partition.
Now's the time to try rebooting the system and see if it actually works. Hopefully, upon restarting you'll be greeted by the chameleon bootloader and the option to select your hard drive. Type 'mach_kernel'. Press 'Enter'. This will boot back into OS X.
Drop mach_kernel_atom_1062 and mach_kernel_atom into the root of your hard drive (the main partition with OS X installed on).
Drop 'Kext Utility' onto your desktop.
Now's the time to update to 10.6.2. Any update after this breaks the ability to patch the sound so it's important to back up the 'AppleHDA' kext from this version in order to keep working sound.
Start the 10.6.2 update and wait for it to finish.
Once completed, reboot the system. Tap 'F8' repeatedly at the BIOS splash screen. At the bootloader type 'mach_kernel_1062' and hit 'Enter'.
Open finder and navigate to 'System/Library/Extensions' and drag a copy of 'AppleHDA.kext' onto your desktop.
It's then safe to use 'System Update' to update to 10.6.4.
Let the update install and the sytem reboot.
Open finder and navigate back to 'System/Library/Extensions'. Drop the 'AppleHDA.kext' from the desktop into the 'Extensions' folder.
Run 'Kext Utility' from the desktop. This will install the new 'AppleHDA.kext' properly.
After letting it run, you should be able to reboot and have 'fully working' (no audio over HDMI) sound.
Cleaning up:
It's now safe to delete 'mach_kernel_1062' from the root of your hard drive. It's also safe to re-enable 'Hyper Threading Technology' and 'Intel XD Bit' in the BIOS.
Enjoy.