For testing purpose only i use Leopard on SpringDale-G motherboard, for that i used:
iPC_OSx86_10_5_6_Universal_PPF5_Final
voodoo kernel
seatbelt.kext
LegacyApple|Intel|PIIXATA from Chipset Drivers
AC97 Audio from Audio Drivers -> Other Audio Drivers in install customisation
PS/2 Keyboard fix from Fixes and Patches -> PS/2 Device Support
I really recomand bying a Mac for real use.