I guess you have a mouse you like, a monitor, and speakers and/or a headset as well. About your os though...
I made 2 builds. The first is your second with a few tweaks. The second is if you need windows. Check 'em out:
http://pcpartpicker.com/p/ijcF
This z68 mobo because after reading reviews, newegg customers like it better than other z68 mobos. OCs, too.
DDR3 1333 or 1600 w/LP heat spreaders that have zero chance of bumping heads with the fan on hyper 212.
You can stick with i5 2500k and 1333 or spend 5 bucks more for 1600 if you may throw in a ivy i7 at a later date.
Just knock off which ever one you don't want by hitting the edit button and remove.
Bumped the storage up to 1TB. Bump it back down if you don't need so much. Decent cost/GB, though.
Antec 300 TWO case: now this one is a big change. It's a higher quality case, though. 1 14cm top fan and 1 12cm
rear fan(switch to front intake?), removable/washable front intake air filter, removable/washable bottom psu
intake filter, cable management, cpu cutout for easy install and removal of large air coolers with back plates(like
the hyper 212), 9 inches wide to easily accept said coolers, room for 12.5 inch video cards, ssd mounts, under-
stated elegance you can mod if you want(dremel the side for a window, toss a led fan in front). USB 3.0 in front.
Other than that, no changes. Just get the optical at newegg for $1 more. Superbiz charges a lot for shipping.
The total is a little over 700 before rebates and a little under 700 after rebates. Now here's the build w/os:
http://pcpartpicker.com/p/ijir
Swapped out hd7850 for a hd7770 and a copy of windows. Smooth for BF3 multi. on ultra* @1920x1200(fxaa
instead of 4xaa, ssao instead of hbao, motion blur off for both better frame rates and to see enemies better).
Anything else(except Metro) should run as well or better. Some games need >1GB vram for some settings, tho.
That depends somewhat on what resolution you run the game at(based on you monitor). Take a look at this:
http://hardocp.com/article/2012/02/14/xfx_r7770_black_edition_super_overclocked_review/
Hardocp found that a mildly OCed hd7770 provided the same gameplay experience as hd6870 and gtx560ti.
If you read the BF3 page(the toughest game on a gpu among the ones tested), you can see hd7770's ability.
That was with launch drivers. Newer ones performance enhance all GCN based cards notably. OCs like crazy, too.
If you own a retail copy of windows 7 64bit, you're all good. If you have an oem copy from a previous computer
(which is tied to the mobo it was first installed on), then you need a new copy. Totals a bit over 700 after rebates.
Again, you can knock the storage down a peg or 2, and don't forget to drop one kit of ram . Hope this helps.
Oh, yeah. About the corsair cx430 psu... It's great. more than you need even if you overclock your cpu and gpu.
Edit: I modded the second of my suggested builds to use the 500GB HDD from your second build. The total(after
rebates) is a little over 700 before you ditch one of the 2x4GB sets of ram and a little under 700 after that:
http://pcpartpicker.com/p/ijIi
You should keep the i5 2500k and overclock it. Some games make use of a fast quad core now(BF3 mulit player,
Skyrim, RTSs, etc). If you get a pentium(like G860) or an i3, you may bottleneck(esp. on a hd7870). Off to lunch...