Actually I've been burning 8 CDs with different versions of EMPIRE EFI (normal, legacy, with ati fix, and even the i7/X58 which contains a fix for ATI) but none did work.
That is why, after having read many threads on the internet about ATI and OSX86, I decided to purchase another graphics card.
Now I am using a GeForce 210, and I am able to get to the installer. I'll try to install Snow Leopard 10.6 tomorrow.

But I have two questions for you:

1. I understand that the required kexts for NVIDIA and audio (VoodooHDA) are included in Empire EFI. When Snow Leopard is installed, does it mean that the kexts will already be installed too, or will I have to install them again manually?

2. Moreover, when Snow Leopard is installed, I have to "patch" the boot not to need Empire EFI CD each time I want to boot. What should I do to patch the boot (I read that i had to use myHack in the post installation folder of Empire EFI). Am I right?

Thank you so much for helping me, I love learning new things