Motherboard decision

[Wheelie182]

Hi Guys, newbie, going to overclock my first pc soon, when i buy all the bits, well im building my first pc as well, its kind like a project i suppose, anyway i've being doing a lot of research into trying to understand all the figures and numbers etc and i think i've got enought info to buy all the stuff, and the overclocking, well i almost understand it but i think i'l wait until ive got all the stuff, and then just trial and error.

am i right in thinking that the pc will shutdown if the cpu gets to hot, do i have to turn this feature on at bios?

but my main question is the motherboard, i know that this it is the most important part of overclocking, i was going to go for the

MSI K8N SLi Platinum Socket 939 Motherboard

but i here that dfi's are the best for overclocking, do you suggest i go for a dfi?