I've been trying many combination of things to get 10.5.8 specifically on to my machine. 10.5.7 works like a charm (iATKOS v7), but when I try iDeneb's lite 10.5.8 version selecting the same drivers/kexts/fixes, I get a kernel panic no matter what kernel I choose for the installation or if I choose none. I've also tried updating the iATKOS install from Software update to no avail.

Hardware that matters:

Mobo: Gigabyte GA-EP45-UD3R
Audio: Built-in Azalia (Requires Voodoo HDA driver)
Video: nVidia GeForce 9800 GT
Network: Built-in Realtek r1000
SATA controller: JMicron (ICH10, requires ICHX fix)

HCL 10.5.8 - OSx86

There's some instructions for your board there.