Despite the negative reports I have had I am thinking of W8 as its got the longest life left in it. I have run the w8 Upgrade Assistant and other than a couple of minor issues I can run W8 without problem.
The question is this. Amazon have the W8 Pro upgrade disc @ £50 which I can use for a clean install (see Tweakhound) but what version does the upgrade have? 32 or 64? (or both?)