You'll be fine with 7, backup your stuff first don't upgrade it wipe and start again. I always partition the drive in two something like 100-200gb for the os drive then the rest for data. Once you have it all installed created a folder on the data drive called my docs and change all your libraries to point there instead of c:\users This way if your os ever goes tits up you can reload it without backing up all your documents again as they'll be on a different drive letter. Windows 8.1 once you get used to it is epic, the performance difference is huge especially file copying it just flies compared to 7 I know 8 upset a lot of people and it was a step too far for non touch devices but we had a lot of this in the switch from 3.1(1) to 95
I have this argument with a family member on Facebook, take great delight in ripping the **** when Apple **** up Like the ssl debacle (not heartbleed) in all of their os that basically completely broke ssl meaning anyone could have nicked your banking details etc. Or the new iPhone lock exploit where people are hijacking phones and locking them demanding money to unlock them