Computer advice needed

I have finally decided to build a new stationary computer for gaming and work usage. In truth, I haven't really bothered staying up-to-date in the past two years as far as new computer components go, so I figure I will find your hypothetical advice of significant avail. Here are the components that I'm considering to invest in:

• Thermaltake M9, Black Midi tower (No PSU)
• Corsair Power supply, 550W Bulk, black, ATX/EPS, 120 mm fan, 4xSATA, SLI
• Gigabyte GA-EP45-DS3L, P45, Socket-775, ATX, GbLAN, DDR2, PCI-Ex(2.0)x16
• Intel Core 2 Quad Q9400 2.66GHz, Socket 775, 6MB, 1333MHz, Boxed with Fan
• Corsair Dominator TWIN2X8500C5D 2048MB, DDR2, 2x1GB(KIT),DHX,E.P.P, CL5-5-5-15-2T
• HIS Radeon HD 4850 512MB GDDR3, PCI-Express 2.0, 2xDVI/HDMI/HDCP
• Seagate Barracuda 7200.11 500GB, SATA-300, 32MB, 7200RPM
• Scythe Mugen CPU Cooler, 120mm Fan, Socket 478/775/754/939/940/AM2
• Samsung DVD-recorder SH-S223Q/BEBN

The price tag for all components is an equivalent of 1152 USD (£781). I am considering to switch the Radeon for a GeForce 9800GT 1G instead, but I am uncertain.

Thoughts?

eveything looks good from here and go with the GeForce 9800GT 1G and if you want more space try the
Seagate Barracuda 7200.11 ST31000340AS 1TB 7200 RPM 32MB Cache SATA 3.0Gb/s Hard Drive - OEM you get more space and if you shop newegg great prices but its your choise

www.IBuyPower.com

Last time I tried to order something of equivalent size from the U.S., they wanted to charge me more than $500 for freight shipping.

I revised the system a bit, and cut the costs by more than 25% to $856.

• Ace Heroes Miditower 480W
• Asus P5QL PRO P43
• Intel Core 2 Duo E8500 (3.16 GHz)
• ATI Radeon HD4850, 512MB, GDDR3, PCI-Express
• DIMM DDR2 667 MHz, 4 GB
• Hitachi Deskstar T7K500 500GB S-ATA/300
• Samsung DVD±RW 22x Dual Layer
• Logitech S-120 speakers 2.0 (part of a bundle offer)
• Microsoft Wired Slim 500, black
• Logitech Optical Wheel Mouse, black

I really wanted a quad CPU at first, but realized I'm more likely to use the system for gaming rather than film editing. The E8500 duo CPU can easily be overclocked to 4 GHz (or closer to 4.5 GHz, but that's a bit risky), which I think should be fine. I'm still not sure about the Radeon HD 4850 GPU, but from what I've read about it, it seems to handle Crysis well.

What would you change, if anything?

You're gonna want DDR2 1066 (rather than 667) for that motherboard.

What would you change, if anything?

As a personal opinion I'd get a Full tower and either the ATI Radeon HD 3870 X2 or the 4870 X2 (most powerful graphic card to this day). They are both more expensive but are also more powerful than the 4850 model. It would be an all around multitasking system that way. As far as the CPU goes, whatever floats your boat on power. I overclocked the AMD Phenom 9950 to 3.0GHz. It's freakin' epic in power. Especially for programs/games/etc that take advantage of the cores. Handbrake video converter, for instance, takes great advantage of this.