I got a new build under way and its main use is going to be fore BF3 and Skyrim on a 1920x1080p 24" Single Monitor heres the specs. Check it out and let me know under what resolutions or settings you think ill be able to play this on with a smooth amount of Fps.
MOB: ASRock Z68 Extreme3 Gen3 LGA 1155 Intel Z68 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard ($122)
You can get 2x4gb ram for cheaper than $50. Crucial and Kingston sells for around $40-45. Do not get Windows Ultimate. It will not aid in gaming in any way and you probably won't need all its features. Get Win 7 Home Premium and save $85. Use the $85 on a Radeon 7850.