You will need a p67 or z68 motherboard for the (K) processors. H67 will work too but has very little OC capabilities & the the (K) processors are MEANT to OC.
Ram is fine can upgrade to 8gb if you want
HD will work
PSU: What GPU are you using & do you plan to upgrade that too?
Right now i dont have a GPU, but im looking at getting the Nvidia GeForce GTS 450(or 440 can't remember)
well how about the 2500?