Here is a spec I did for some one else earlier:
Intel Pentium Dual-Core E5200 "LGA775 Core 2" 2.50GHz (800FSB) - Retail
Abit IP43 Intel P43 (Socket 775) PCI-Express DDR2 Motherboard
GeIL 4GB (2x2GB) PC2-6400C4 800MHz Black Dragon DDR2 Dual Channel Kit (GB24GB6400C4DC)
Powercolor ATI Radeon HD 4850 PCS Extreme 512MB GDDR3 TV-Out/Dual DVI/HDMI (PCI-Express) - Retail
Corsair VX 450W ATX PSU (CMPSU-450VXUK)
Total : £345.39 inc free delivery
You could always spend the bit extra on a P45 board, rather than the P43.