hi all i need some help in finding & installing the kext for my motherboard

this is all in safe mode
I have installed Mac with Iboot 2.0 ver 10.6.3 and then install update 10.6.4 & rebooted. Then installed 10.6.5 & 10.6.6 & BridgeHelper and rebooted and thats where i am stuck in safe mode with no Ethernet or sound



MB: EVGA nForce 790i Ultra SLI 132-CK-NF79-A1
-no Ethernet - Generic Marvell Yukon 88E8057
-no Sound - Audio 7.1 channel, Azalia (HDA)
CPU: Intel Core i7 2.8GHz LGA 1156 95W Quad-Core Processor
VC: GTX 295
HD: Seagate Barracuda 7200.11