Memory Speed

[Tomwilled]

I am putting together a new build spec based on the Intel 8500 chip but cannot decide what memory type ie DDR2 or DDR3 and at what speed.I would not like to rule some overclocking,any help please?

 

[Tomwilled]

Any help please,should have perhaps said I am thinking of basing the new build on an Asus x48 motherboard.