Re: OS help
If you have a decent specced machine, I would go with Vista, because of DX10 support, and also because it's just works like it should now.
I'm running the 64 bit edition (I would recommend going with 64 bit over 32 bit), and I've had zero problems with it. I don't think I could go back to XP.
AMD Phenom II X4 955 BE @ 4.0GHz + TU120E lapped - MSI 770-CD45 AM3 - 2x2GB OCZ DDR3 1333MHz - Sapphire HD 4870 - Samsung Spinpoint 500GB 7200RPM 16MB cache HDD - Tagan TG600-BZ Piperock - (Currently open test bed) - Windows Vista Home Premium 64bit.