I've been out of the loop for a while now, so bear with me. I've noticed my system is starting to get long in the tooth and lag some--it even has vista still installed!--so I sweet-talked my wife in letting me build a new system:
I'm moving from a socket 775 e8500 on an x48 chipset with a gt260. Pretty sure I want to go with a 2500K or 2600K intel (read about their great oc'ing ability)...but am unsure as to whether P/H/Z67 is right for me. I'm also completely lost on video cards as so many have come out since I last looked at them (the 295 was king then). I am not a loyal slave for either company I just want top peformance for my price on the card--about 200-300 bucks--5 series or 69 series?. Last but not least....should I still hold for Ivy Bridge, or stay with my choice above in Sandy Bridge? Also unsure what my memory speed should be these days as a minimum (12800?)
What I do--lots of movies and music--some gaming (little bit of wow every couple of years, but stuff like the total war series is my favorite), and anxiously awaiting D3 and next chapter of SC2--on a 32" 1080p tv. I'm kind hoping the card would be semi quiet as we watch tv in th e same room.
The 2500k would be enough for your needs. The extra 100 dollars on the 2600k isn't really worth it, unless you do some heavy media work.
The major difference between P/H/Z67 series is the P series overclocks the CPU, the H series overclocks the graphics power on the 2500k, the Z series does both. The Z series also has SSD caching if you are interested in that, along with being able to switch from your graphics card to the CPU graphics chip.
Since you are buying a 300 dollar graphics card, the H series isn't needed. So your main choices are the P/Z series. I suggest the Z series because the price difference between the two motherboards with the same functionalities and slots aren't that much.
Go the the 6k series for your graphics card. Or the 500series from Nvidia. The price-per-performance ratio is really close between the two companies so the only real deal breakers are what functionality you want. Nvidia gives you CUDA/Physx support while AMD gives Eyefinity.
As stated the 2500k is going to be the sweet ticket price/performance wise.
Look at the ASRock Z68 Extreme 4 motherboard. I would suggest either a Radeon HD 6950 or Nvidia GTX 560Ti. What would really help would be your budget, resolution, and games you play?