1) Do not chase combo's unless you would have bought both parts individually anyway.
2) For a new build, I would look first to newer gen parts. They are built on smaller mfg technologies and usually run cooler with less power.
3) 2500K is a fine cpu chip. If you live near a microcenter, they will sell you one for $170, A ivy bridge 3570K for $190.
I would not upgrade a 2500K to a 3570K, but for a new build, I would look at the 3570K first.
4) Same approach for the graphics card which is the main engine for gaming. Look at a 7850, or even a GTX670. I think the GTX660 is right around the corner, and should provide some good competition to amd in that price category.
5) I really think any new build with a "K" cpu should include an aftermarket cooler. A $30 cm hyper212 would run cooler, be quieter, and let you OC better. The backplate mount will be much easier to install than the stock Intel pushpin mount.
6) Corsair ram is good, but buy a low profile kit, or one with no heat spreaders. Tall heat spreaders are not needed with 1.5v ram, and can interfere with oem coolers.
7) Unless you will store lots of larger files, like video's, consider starting with a 120gb SSD instead. That will be large enough to hold the os and a handful of games. Everything you do will be much quicker. You can buy an Intel 330 120gb drive for $90 after rebate and using promo code EMCYTZT1783 today. http://www.newegg.com/Product/Product.aspx?Item=20-167-121&nm_mc=EMC-GD062012&cm_mmc=EMC-GD062012-_-index-_-Item-_-20-167-121