Here is the crossfire rig:
PCPartPicker part list:
http://pcpartpicker.com/p/NbeD
Price breakdown by merchant: http://pcpartpicker.com/p/NbeD/by_merchant/
Benchmarks: http://pcpartpicker.com/p/NbeD/benchmarks/
CPU: Intel Core i5-3570K 3.4GHz Quad-Core Processor ($189.99 @ Microcenter)
CPU Cooler: Cooler Master Hyper 212 Plus 76.8 CFM Sleeve Bearing CPU Cooler ($26.69 @ Outlet PC)
Motherboard: ASRock Z77 Extreme4 ATX LGA1155 Motherboard ($114.99 @ Amazon)
Memory: Corsair Vengeance 8GB (2 x 4GB) DDR3-1600 Memory ($47.98 @ Amazon)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($69.34 @ Amazon)
Storage: OCZ Vertex 4 128GB 2.5" Solid State Disk ($129.99 @ Microcenter)
Video Card: Gigabyte Radeon HD 7970 3GB Video Card (2-Way CrossFire) ($389.99 @ NCIX US)
Video Card: Gigabyte Radeon HD 7970 3GB Video Card (2-Way CrossFire) ($389.99 @ NCIX US)
Case: Cooler Master HAF 922 (Black) ATX Mid Tower Case ($79.99 @ Newegg)
Power Supply: SeaSonic M12II 750W 80 PLUS Bronze Certified ATX12V / EPS12V Power Supply ($79.99 @ Newegg)
Optical Drive: Samsung SH-224BB DVD/CD Writer ($17.98 @ Outlet PC)
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) ($89.98 @ Outlet PC)
Total: $1656.90
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-03-30 00:53 EDT-0400)