I have a friend wanting to put OS X on their system.

I am trying to find out what the best distro would be best for her.

Now I am fairly new to this because I have no need to run OS X on a non-apple computer as I own a MacBook Pro and PowerBook. But that is besides the point.

I came across the following distro and just wanted to hear what others hear have to say and recommend. Even pointing me in the right direction would be great (a link or anything). I would very much appreciate it. iDeneb v1.4 10.5.6 (I want to have the latest 10.5.6 running on their machine by the way which I know 10.5.7 is imminent) but no biggie. iDeneb v1.4 10.5.6 Released!

System specs:
AMD Athlon 64 X2 4200+ Processor
ASRock ALiveNF6P-VSTA Motherboard
G.SKILL 4GB (2x2GB) DDR2
OnBoard - # Integrated NVIDIA GeForce6-class graphics DX9.0 VGA, Pixel Shader 3.0, Max. shared memory 256MB
Western Digital Caviar 500GB SATA

If any other specs or information is required. Please do ask and I'll get that info. This system would probably be dual booted with Vista if that matters.