overclocking core i7 cpu and ram related question

I've already post this question on the overclocking union board but nobody answered so i'm giving it a try here...

So, i'm a bit confused about overclocking and ram for the i7. I want to buy a core i7 in june, probably a 920, which I will overclock to maximum 3,2 ghz and I was wondering what type of memory do I need? Do I really need 1600 Hz Ram or 1333 is alright...if 1600 hz is the one, 9-9-9-24 is a good timing or i need 8-8-8-20 ? Sorry if it sounds stupid but I really dont know much about overclocking and ram

thanks