if you havent already seen this. check it out...
www.osx86project.org
Mac osx running on pc platform.
I have it triple booting on my computer at home.
I run XP pro, Ubuntu Linux and osx.
Osx runs ok, not bad, some things don't work, but overall its just fun to play with.
Ubuntu linux is cool, I like it, but I still stick to xp most of the time.
I only installed linux and osx because I could and wanted to play with them...
Sounds like you have a nice machine, I am sure it will love a true 64 bit OS that works properly.
Alon