Just to add a couple of things.
Asrock boards are really good, great value for money from their bottom of the range to their top of the range and cheaper than the big names.
I got a 970 Extreme 3, at the time is was above middle of the range and i am really pleased with it, I have also built budget machines for other people using Asrock boards. all still working after 4 years or more.
Case wise, I suggest to go for something that will last, I kept buying cheap case, about around the £20 mark, but every time i updated the machine I had to get a new case as the old one was falling apart and warped. So I went for a
coolermaster Haf,. A mate of mine got the big version, I did not want anything that big, but i wanted a sturdy case, which is why i went for the one I linked too.
Of cause it depends on what size you want the case.
OS wise, nothing wrong with windows 7, well there probably is, but It works fine, it got a few more years of life and compatibility wise it is fine.
Windows 8 is also ok, it boots up fast, even on a restart, it is pretty fast, software seems to run a bit smoother, bulky software like Photoshop and Vegas seems to load in quicker, it is better at managing memory. Compatibility wise, there are a few problems, but I got most sorted now, I still have the odd problem with my wi-fi mind you.
The metro UI, you either love it or hate it, I myself don't use it and got a start menu added.
Adrian
Desktop machine now powered by windows 7 pro 64bit , laptop by ubuntu
ALLPAY Wireless broadband