If you aren't up for building it yourself, and just want something that works out of the box, one decent option is
this. Select "NVIDIA GeForce GTX 460 1GB 16X PCIe Video Card" as the video card, and "600 Watts - XtremeGear Power Supply - SLI/CrossFireX Ready" as the power supply. Should end up at $1,016. Free shipping to boot. That's a very decent price for a very decent pre-built system. i7-950, 1 TiB hard drive, 6 GiB of RAM, and a very good video card. That should cover the listed requirements.