I will be Building a new computer Monday and I cant decide if I want to run windows 7 or 8 on it. Gaming is what I am building it for and what I want to run smoothly. Also (and I know I really should know this) do I need the 32 or 64 bit version?
Windows 8 is more like a future Proofing. Just like Vista was With XP, but unlike Vista, Windows 8 is faster. If Your New computer will use brand New Components then I would recommend Windows 8. The only thing to know is that it's different than other Windows versions, which is a barrier for a lot of users, get past that barrier & I think you will like it.
Now & throughout January 2013 Windows 8 is fairly cheap aswell.
And yes, 64bit Version is what you will use. Then you can utilize all the memory & processors.
I just built a system myself and I went with Windows 8 (non-professional) OEM systems builders edition. It was $70 on Amazon. If you're starting from scratch I think its the cheapest way to get the Windows OS and there's the future proofing aspect.
If you have access to a Windows 7 license I guess I would go with that since it saves money. I wouldn't be surprised if Windows switched to the yearly OS upgrade plan like Apple.
Someone also recommended this to me too late:
Its a trial version of Windows 7 (legal) and you apparently can upgrade to 8 for the upgrade price. I didn't try it because I already ordered mine, but maybe worth a shot if you're starting out.