[Chaos Residue]

For $870 I found this:

CPU - i7-2600K ($325)
Newegg.com - Intel Core i7-2600K Sandy Bridge 3.4GHz (3.8GHz Turbo Boost) LGA 1155 95W Quad-Core Desktop Processor Intel HD Graphics 3000 BX80623I72600K

Motherboard - Intel BOXDZ68BC ($200)
Newegg.com - Intel BOXDZ68BC LGA 1155 Intel Z68 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard

Video Card - PNY Quadro FX 580 ($180)
Newegg.com - PNY VCQFX580-PCIE-PB Quadro FX 580 512MB 128-bit GDDR3 PCI Express 2.0 x16 Workstation Video Card

Heatsink/Cooler - Corsair CAFA70 ($40)
Newegg.com - CORSAIR CAFA70 120mm A70 Dual-Fan CPU Cooler

RAM - G.SKILL Ripjaws X Series 8GB (2x4GB) ($47.00)
Newegg.com - G.SKILL Ripjaws X Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9D-8GBXL

Power Supply - OCZ ModXStream Pro 600W ($75.00)
Newegg.com - OCZ ModXStream Pro 600W Modular High Performance Power Supply compatible with Intel Sandybridge Core i3 i5 i7 and AMD Phenom

Do you have a case already?