Motherboard for pentium D 820

If you want to use DDR3 ram then go for Gigabyte GA-G41MT-S2PT @ 3.5K. But if you're having older DDR2 Rams then get the Gigabyte G41 Combo motherboard which has both DDR3 (2 slots) and DDR2 (2 Slots) Ram slots.

Does my processor supports ddr3 memory ?
If yes then i'll go for s2pt

Buddy, none of the LGA 775 chipset based Processors have integrated memory controller and the memory controller is situtaed in the Motherboard. So motherboard manufacturers can provide both DDR2 and DDR3 memory support by adding an appropriate Memory controller, Processor support is irrelevant as it is not communicating directly with the Ram but doing so through the memory controller present in Motherboard. So you can get the DDR3 Gigabyte Motherboard I have suggested and add some 1333 MHz DDR3 Ram, plug your Processor and you're ready to go.