I am going to go the Boot Camp route, as all I would need is a copy of Windows. I've already set aside 200GB partition on one of my HDDs for Windows.
I read that I can buy Windows 8 Pro OEM System Builder for Personal Use, but it comes with no Microsoft Support. If I buy Win 8 Pro System Builder at a Microsoft Store does it come with support?
Buying OEM System Builder at Amazon is only $135, but buying at the Microsoft Store is $199. What's the difference between the 2 products? Does the cheaper OEM version have bloatware on there? I'd pay extra not to have all the gross bloatware!
An important consideration in choosing the OEM version is that unlike the retail version which costs more, it is tied to the one system it is originally installed on. If you get a new Mac and want to use it again, you are likely to have problems because Windows will as usual phone home on install to validate and notice the hardware is not the same anymore.
The OEM version is intended for system builders, including enthusiasts at home building their own PCs to install on those systems for their useful life and that is it. A retail version, you are free to install and remove and reinstall elsewhere as you see fit. There is a difference and people often seem to not be aware of this.
It was more money but I purchased Windows 7 retail myself so that when I get my next iMac, it won't be a problem to continue using it. I expect Windows 7 is going to have a long life, like XP has, as user adoption of Windows 8 has been abysmal - worse than Windows Vista so far. A lot of games don't even require DirectX 10 yet, never mind DirectX 11, so again, Windows 7 has a long life ahead of it for a gamer at least. I'll go through at least one Mac upgrade during its useful life, if not more.
By the way, you can sometimes get away with telling an OEM copy on install that you have "upgraded" hardware even though it is actually a completely different computer but I would not count on this always working.
So, my advice is just spring for the retail version and spare yourself any hassles and headaches down the road.