Hello,
I recently built a computer similar to the specifications you are after, but I adjusted the build to meet your needs.
Intel Core i7-2600 Sandy Bridge 3.4GHz (3.8GHz Turbo Boost) Quad-Core Processor
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115071
ASRock HDMI SATA 6Gb/s USB 3.0 Micro ATX Intel Motherboard
http://www.newegg.com/Product/Product.aspx?Item=N82E16813157233
SAPPHIRE Radeon HD 6870 1GB 256-bit GDDR5 PCI Express 2.1
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102909
G.SKILL Ripjaws Series 8GB (2 x 4GB) 240-Pin DDR3 Memory
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231311
Western Digital Caviar Black 1TB 7200 RPM 64MB Cache SATA 6.0Gb/s Hard Drive
http://www.newegg.com/Product/Product.aspx?Item=N82E16822136533
LITE-ON Black CD/DVD Burner
http://www.newegg.com/Product/Product.aspx?Item=N82E16827106289
Antec EarthWatts EA650 650W "compatible with Core i7/Core i5" Power Supply
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371015
ZALMAN CNPS9500 AT 2 Ball CPU Cooling Fan/Heatsink
http://www.newegg.com/Product/Product.aspx?Item=N82E16835118003
The case is more personal preference than any other component so I will just leave that up to you. This build will cost around $900 plus whatever you pay for the case. All in all you will pay under $1000 for one hell of a PC!
I buy all my parts from Newegg, as do most of the online tech community; they are extremely reliable and well priced . If you have any questions feel free to ask.
P.S.- Check out this site if you want more help and to learn more about new system builds:
http://www.tomshardware.co.uk/forum/forum-13-322.html