After some consideration i decided to go for

Intel Pentium D 820 2.8Ghz Skt 775 Fsb 800 2 x 1Mb Cache Retail £177
Abit AL8 £99.82 inc
240-pin DIMM DDR2 £71.66
1 x Barracuda 7200.7 Hard Disk Drive 80GB SATA Native Command Queuing 7200RPM - OEM £40
2x Barracuda 7200.8 Hard Disk Drive 160GB SATA 7200RPM - OEM £130 inc
Enermax Noisetaker 535W ATX V2.0 £70
AOpen 16x DVDRW Chameleon Retail £30
Gigabyte GeForce FX5750 128MB PCI-E £58
Any case no psu £30


TOTAL :£730

It goes above £600 budget but i put in dual core cpu.
Any comments welcome.