If you are really serious about this, go for Dell XPS 720 H2C
Dell XPS 720 H2C Edition System Configuration
Hardware
Processor Intel® CoreTM 2 Extreme quad-core processor QX6800
2.93 GHz at 3.73 GHz, 1066 MHz FSB, 2x 4 MB cache
Motherboard Dell XPS720, BIOS: Phoenix A00 (05/03/07)
nVidia 680i SLI chipset
Memory 4x Corsair Dominator CM2X1024-8500C5D PC2-8500
4x 1024 MB, Overclocked 1066MHz, CAS 5-5-5-15
System Hard Drives 2x WDC WD1600ADFD-75NLR1 RAID 0
160 GB, 10,000 RPM, 16 MB Cache, SATA 1.5 Gb/s
Storage Hard Drive 1x Hitachi HDS721010KLA
1 TB, 7200 RPM, 32 MB Cache, SATA 3 Gb/s
CPU Cooling System H2C Ceramic Liquid Cooling
Floppy Drive 13-in-1 media card reader
Optical Drives LG GSA-H31N 16x Double-Layer 16x DVD+/-RW
PHILIPS BD-RE BDD1001 Blu-Ray Disk Writer
Case 10-bay Aluminum BTX tower case
Expansion Slots 2x PCIe x16, 1x PCIe x8, 3x PCI, 1x PCIe x1
Front Panel Ports 2x USB 2.0, 1x IEEE-1394 FireWire, Headphone/Mic
Rear Panel Ports 5x USB 2.0, 1x IEEE-1394 FireWire, PS/2, Network
Graphics Cards 2x nVidia GeForce 8800 Ultra
612 MHz GPU, 768 MB RAM (1080 MHz)
Physics Processor Ageia PhysX, driver 1.0.6.0
Network Broadcom NetXtreme 57xx Gigabit Controller
8-Channel Audio Sound Blaster® X-FiTM XtremeMusic Sound Card
Power Supply 1000W 5-Rail Power SLI/CrossFire Compatible
Software
Operating System Microsoft Windows XP Pro 5.1.2600 (32-bit)
Microsoft Windows Vista Ultimate (32-bit)
DirectX Version 9.0c (4.09.0000.0904)
Platform Driver Intel 6.0.6000.16386
Graphics Driver 7.15.11.5824 - nVIDIA ForceWare 97.94
*www.geardigest.com/2007/05/22/dell_xps_720_h2c_hot_and_cool/