2k will build a great gaming Rig,
Please fill in the build questionnaire Rv posted and get your screwdriver ready,
because you are building it yourself, if your working on bang for buck cheaper,
The 2500k can overclock to an i7, the difference between the 2 is that the i7 has hyper threading and is better for encoding and video editing. So i perfer the 2500k because you can overclock with ease to 4.0+ and it is fast.
This motherboard is a wonderful Overclocker, it is so easy a caveman can do it. It is also the Z68 so it has better features over like say a P67. It's just a great MOBO in all, and keep in mined to look at MSI and ASUS brands as well as they offer ones just as sweet.
This RAM will do along with any other great brand (G.Skill, Patriot ect.) and all you need is 8GB even if your encoding or using big programs. The one you listed above is 12GB, you will not even use half of that so it is overkill and your overpaying for it.
These GPUs will do wonders right now in the gaming world. The thing about these are you can go with lower ones like the Nvidia 470GTX or the Radeon 6950 and still be fine because when you SLI or CrossFireX these babies there going to max out any game right now.
This PSU has 4 x 6 PCI connectors so it's ready for some SLI or CrossFireX and it's one of the best PSU brands out there so you cant go wrong.
Now you just need a good case, OS, HDD, and DVD Drive and whatever else you need. I will say that the Antec 900 V3, NZXT Phantom, and Coolmaster HAF 922 are all wonderful cases along with alot of other brands.
What is the resolution of the display you have? The reason why I am asking is that depending on the resolution we can tell you if you will need a Crossfire or SLI solution to begin with or can a single card solution handle it. Anything below and including 1920x1200 will can be handled with one card, but multiple monitors and 30" 2560x1600 or 27" 2560x1440 will need a SLI/Crossfire solution.