If you don't want to go the "get" route, you can spend a little more to get an O.S.
Also, if you don't plan to overclock, I would just get a Corsair CX 600W PSU since I think that is a little bit cheaper.
Never, ever, pirate an OS. It's not worth the hassle. To the OP, get an OEM version of Windows 8.1 or Windows 7 (Not 8.0.) It'll cost you 99 USD at Newegg. So it will cost the op over 750 USD even with your build. AMD processors aren't worth it either. But since the Op wants something cheap, they won't be able to afford a good intel.
Last edited by coldReactive; 04-01-2014 at 10:51 AM.