Architecture and Gaming i7 Build

APPROXIMATE PURCHASE DATE: This week

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: Gaming (Crysis, COD MW2 etc.), University stuff (Architechture) and normal stuff (internet, word etc.)

PARTS NOT REQUIRED: Need everything

PREFERRED WEBSITE(S) FOR PARTS: Umart-http://www.umart.com.au/newindex2.phtml?bid=5

PARTS PREFERENCES:

Intel Core i7 920
Asus P6T Deluxe V2 LGA1366 X58
G Skill 6G(3x2G) DDR3 PC12800 9-9-9-24
Samsung 1TB F3 SATA II 7200RPM 32M
Sapphire HD5850 1G GDDR5 PCIE 2D HDMI (Should I go with a workstation card to run the architecture programs?)
Antec Nine Hundred 2 Black Case (No PS)
Corsair HX-750
LiteON IHAS324 SATA DVD-RW 24X Black
LG W2253TQ-PF Gloss Blk 2ms
D-Link DWA-547 RangeBooster N650 Wireless LAN PCI Adapter
Logitech Deluxe 250 Desktop USB
Logitech X-140 2.0 Speakers System

OVERCLOCKING: Maybe SLI OR CROSSFIRE: Maybe

MONITOR RESOLUTION: 1920x1080

ADDITIONAL COMMENTS: Budget $2400AUD. Suggestions on GPU, do I need to go with a workstation card (I'll need to run ArchiCad and Microstation for Archetecture course) or can I stay with the 5850? If I do stay with the 5850, I may look at Xfire in the future.