if you still have a budget of £300 available :
OCZ 2GB (2 x 1GB) PC2-6400C4 Dual Channel Platinum Revision 2 XTC Series DDR2 (OCZ2P800R22GK) £37.99 (£44.64)
Intel Core 2 Duo E2180 "LGA775 Conroe" 2.00GHz (800FSB) - Retail £49.99
(£58.74)
EVGA nForce 650i Ultra (Socket 775) PCI-Express DDR2 Motherboard (122-CK-NF66-T1) £49.99 (£58.74)
OcUK ATI Radeon X1950 Pro 512MB GDDR3 HDTV/Dual DVI (PCI-Express) - Retail £65.99 (£77.54)
Corsair VX 450W ATX PSU (CMPSU-450VXUK) £36.99 (£43.46)
Sub Total : £240.95
Shipping : £8.95
VAT : £43.73
Total : £293.63
OCZ 2GB (2 x 1GB) PC2-6400C4 Dual Channel Platinum Revision 2 XTC Series DDR2 (OCZ2P800R22GK) £37.99 (£44.64)
Intel Core 2 Duo E2180 "LGA775 Conroe" 2.00GHz (800FSB) - Retail £49.99
(£58.74)
EVGA nForce 650i Ultra (Socket 775) PCI-Express DDR2 Motherboard (122-CK-NF66-T1) £49.99 (£58.74)
OcUK ATI Radeon X1950 Pro 512MB GDDR3 HDTV/Dual DVI (PCI-Express) - Retail £65.99 (£77.54)
Corsair VX 450W ATX PSU (CMPSU-450VXUK) £36.99 (£43.46)
Sub Total : £240.95
Shipping : £8.95
VAT : £43.73
Total : £293.63