Hello John,
Thanks for that info, I'll be getting a 64-bit of whatever the OS is offered as standard, as that is the best for the future, however, I also read the wikipedia page on WIN 7 and it states that I can install WIN XP as an extra OS, but, only on the Pro/Enterprise/Ultimate versions, not on the Home Basics and Premium editions, they also only have a ceiling of 16GB RAM, so, should I require more, it's probably not the best version to personally obtain.
Cheerz. ex.
That is correct regarding the Windows XP. It's done as a Virtual Machine running on Windows 7. If you move up to Windows 8.1, you can run a licensed copy of Windows XP also in a VM, however, you will also need the pro version for that as well to enable Hyper-V which has replaced the Microsoft Virtual PC used previously. To be honest, since I've moved beyond Windows XP, I have found fewer and fewer reasons to go back to it. The newer operating systems have the same features as XP plus a lot more.
Yes, the OS limit for the home version is 16GB. The Pro or Ultimate is highly recommended even if it costs a bit more due to better memory and network feature support. With Pro or Ultimate, you get nearly the sky's the limit with the amount of RAM that can be handled by the OS which right now is more than what can be physically fit on most home-user grade motherboards.

@Nicky, I agree the video card required will be the TI as a base, but you'll need quad-SLI TIs to achieve the performance needed for top game play.
John