IN Intel Core 2 DUO E6300 "LGA775 Alendalle" 1.86GHz (1066FSB) - OEM
£114.95
MB-003-AK Asrock ConroeXFire-eSATA2 (Socket 775) PCI-Express DDR2 Motherboard (MB-003-AK)
£51.95
MY-014-GS G.Skill 2GB DDR2 NR PC2-6400 (2x1GB) CAS5 Dual Channel Kit (F2-6400PHU2-2GBNR) (MY-014-GS)
£114.95
GX-025-BG BFG 3DFuzion GeForce 7600 GT 256MB GDDR3 TV-Out/DVI (PCI-Express) - Retail (GX-025-BG)
£99.95
HD-051-SE Seagate Barracuda 7200.9 80GB ST3808110AS SATA-II 8MB Cache - OEM (HD-051-SE)
£29.50 £29.50
CA-000-AR Arctic Cooling T1 Silentium Midi Tower Case - 350W Seasonic Silent PSU (CA-000-AR)
£47.95
CD-038-PO Pioneer DVR-111DBK 16x16 DVD±RW Dual Layer ReWriter - (Black) OEM (CD-038-PO)
£21.95
Arctic Cooling Alpine 7 CPU Cooler (Socket 775) (HS-021-AR)
£6.25
Subtotal £487.45
VAT £85.31
Total £572.76
40 quid more than your spec but you get 2 gig of ram and a faster gfx card in the 7600 GT.
You should be really looking at getting 2 gig of ram for a gaming system now.
If you dont have enough wedge then I would wait a few weeks until you do.