Hello,

I would look @ www.kexts.com there are very usefull kexts!
For your graphicscard i already found one: http://www.kexts.com/view/229-natit.html

The easiest way to get your soundcard working is to try an other voodoohda, there are some which are optimized for alc888.
But there are more possibilities to get it working. One way is to use HDAEnabler + an patched AppleHDA.kext.
The other and the best way is to get it working with an patched DSDT + AppleHDA.kext.

If you have some questions i will try to help you.

Greetz