Tip for a system builder:
Get a good case and PSU. These are worth investing in because they will last you for years, if you get good enough ones, that is.
Also in real world situations getting a really good graphics card is a good idea, you will get the most performance form that. The new DirectX11 cards are out, get a good one if you can and it will last you a long time also. A Radeon 5850 is the best performance/$ at the moment if you can get a good deal.
I would go for an 1156 motherboard and an 15 750 CPU, and 4Gb of DDR3 RAM.
I wonder if you could squeeze that out of $1000. I wonder if there would be enough room in the budget for an i7 860 instead......
I dont know what US prices are like.