Uncensored2008
Libertarian Radical
I'm one of those people who tends to hang on to the old technology. My motherboard is an ASUS P5Q with DDR2 RAM. I built the PC in 2009. Yeah, I've thought about building a new one. It was a real pain to install Windows 8. I'd get to where I was almost there, and it would hang up. I then had to flash the BIOS for Windows 7, since Windows 8 wasn't around 4 years ago. After I did that, then the software loaded up quite nicely. I have noticed that if you ignore the useless metro squares, there is not much difference between Windows 7 and 8.
Your mobo has 8 SATA-2 connectors. Easy enough to through a new drive on without doing a new build.
I initially hated Windows 8, only using the desktop and command line. But I bought a Surface Pro and have grown to like the interface a bit better. I still won't put it on a desktop, but for a touch screen, it does a good job. And you're right, except for Metro/Modern - there is very little difference between 7 and 8. That's Microsoft. The real operating system is Longhorn, the Vista/7/8/8.1 are just changes in the presentation layer. Longhorn is the best operating system on the market - by a long way. Windows 8 is a good system, even if you hate the UI - it has a stable and mature core, multi-threading that puts Ubuntu and other Linux distros to shame, and can do grown up work, unlike the Cat named systems.