Hello, I'll try to give you a hand here! I have the same laptop and I have succesfully installed macos, and all beside graphics works fine.
First you need to have iDeneb 10.5.5
In the customisation you need to check the following (hope to remember all of them):
- AMD patch
- 9.2.0 Sleep
- Azalia audio (it will not work but I will tell you how to fix it later - after boot)
- Wired net: Realtek RTL8111 (didn't test if it works but I don't give a rat's ass if it doesn't)
- Wireless: Broadcom
- Macbook smbios
- Firewire removal
I don't remember what else was in the downside of the customization, but if you have doubts post the question here and I will try to help you ASAP.

Note: DO NOT CHOSE any chipset!
The hdd was configured with dual-boot(vista&W7) and it was not f-uped by the macboot.

The fix for the audio: --- The method is posted by rinjose on Insanelymac.
"download http://rs222.rapidshare.com/files/13.../ALC268FIX.zip
install everything in it except installer2.
before rebooting the sytem goto system/library/extensions and delete alcinject.kext
reboot the system."

The fix for an eventual WiFi malfunction: --- Fix tried by Yoplaid still on insanelymac
"-open the script bcm43xx_enabler.sh in textedit and add <string>pci14e4,4315</string> (somewhere between the other strings).
-then sudo ./script bcm43xx_enabler.sh"