I have three tips based on what I see. Swap the 580 for a 1060- personally, it's more bang for the buck as I see it. 6gb model should be more than enough. Or get a 1050ti if you're okay with something a bit less powerful.
Of course, in doing so you hike up the cost slightly but in turn, I have a solution:
Instead of buying Win 10 from Microsoft, try
this site, which I've used myself a few times so I can vouch for it. They got Win 7 to Win 10 keys on the cheap. Much better than paying one-hundred-fucking-dollars for a lukewarm OS.
Third tip. Get an M.2 SSD. They're fucking fast. I recommend putting the OS on that, games on the regular SSD, and all else on the HDD, including important documents. It'll obviously last the longest of the three. Or use the M.2 for Linux- it's up to you.