thats a good place. If you are only going to play wow and the sims, then you don't need the most powerful graphics card. I'd say a 7850 would be more than powerful enough for both. If you want something cheaper, a 7770 should still be good enough to play wow very well.
You will also need a case, a power supply maybe a DVD drive and a hard drive.
That is a top of the line processor. A 7850 would easily handle your games, however, I wonder whether you could save money on a cheaper CPU. Do you plan on overclocking? If not, you do not need the 3570k. In fact, an i3 + 7850 would meet your requirements.