Budget Gaming Rig - Suggestions

Hi,
I'm wanting to build my first P.C. and I'm trying to start out fairly cheap.

I'm using my Xbox 360 for the majority of my gaming, so the main uses of the P.C. will be general surfing, watching films and the odd new game here and there (Guild Wars 2 mainly, when it comes out).

Here's what I'm planning on buying:

Processor

• Intel Pentium Dual Core E5200 2.5GHz Socket 775 800FSB 2MB Cache Retail Boxed Processor
• http://www.ebuyer.com/product/148715

Motherboard

• Can't decide which motherboard to get - looking for suggestions (preferably available on eBuyer)

Graphics Card

• XFX 9600GT 512MB GDDR3 Dual DVI HDCP HDTV out PCI-E Graphics Card
• http://www.ebuyer.com/product/148012

Hard Drive

• Seagate ST3500320AS 500GB Hard Drive SATA II 7200rpm *32MB Cache* - OEM
• http://www.ebuyer.com/product/130826

RAM

• OCZ 2GB Kit (2x1GB) DDR2 800MHz/PC2-6400 CL 4-4-4-15 PLATINUM XTC
• http://www.ebuyer.com/product/116755

Case

• Casecom Black Mid Tower Case - Front Blue LED 120mm Fan - With Side Window
• http://www.ebuyer.com/product/115479

Power Supply

• Extra Value 550W ATX Silent Neon PSU - 12cm Fan/PPFC
• http://www.ebuyer.com/product/102994

Monitor

• Samsung SM2032BW 20"TFT Monitor Widescreen 1680x1050 3000:1 300cd/m2 2ms VGA/DVI-D Glossy Black
• http://www.ebuyer.com/product/132115

That's about it.
So basically I'm looking for motherboard suggestions, and opinions on the rig in general.
Any help is much appreciated, thanks!