OSX Dual Boot / Alienware Auroa

Im not totally new to this so you can hit me with the info.

At my new workplace i do video editing full time on Mac's and now i need a Mac at home but i really dont want to junk my monster Alienware machine and buy a Mac when i have a power house here that could be setup with OSX, i hope.

Basically along time ago before my hardware was supported i tried to drop an OSX on my machine with failure of mass proportions! I was wondering if i can get a little help please, below is my specs can some one please recommend what version of OSX i should use to get OSX running on my machine. Should i use the original Leopard which i currently have at home on my wifes Mac. Or should i use a version floating around on the net, which i tired last time with not much success.

Sorry im at work now so these specs are off the top of my head.

Alienware Aurora
-------------------------
Intel i7 - 920
Intel X58 chipset - i believe!
Mobo : Alienware 0H869M A00
ATI 5870
8gig DDR3
Seagate Barracuda 1TB 7200 RPM HDD

I will be wanting to do a duel install on one HDD as i dont have 2 currently. I already have windows 7 running on this machine, so i believe i just have to make a HFS+ partition on my current HDD to allow the install of OSX.

What version of OSX should install, original which i already have or the can someone tell me which of the many online versions should i use such as iATKOS S3 etc. Any special things i should do with my system to get a higher rate of success when installing OSX. I have gone through most of the process before but failed, this time i want in!

Also i was looking at iATKOS S3 and seen the install list i have to choose from if i want to install it, what should i be selecting from the list and what should i live alone with my system. I believe i can get my ATI driver from netkas.org once im in the OSX and its working.

iATKOS S3 Install list

Much appreciated guys!