Additional Comments: I would like to be future-proof for at least three years, but I don't think that I'll be upgrading to Ivy Bridge or PCIe 3.0 next year or the year after. Honestly, I am hoping this holds me over until the next gen CPUs and graphics cards.
CPU - I am set on this
Motherboard - I am not so sure in, but I hear that Gigabyte boards aren't that great with Z68. I am experienced with ASUS only, but I am willing to consider other options other than ASRock or ASUS. I will consider other chip sets also since I am going to have a dedicated GPU.
RAM - I am confident in this but will consider other options
GPU - I am confident in my selection but I am considering the 2GB version since its only ~$30 more
PSU - I want modular and I am considering Corsair and Antec (I currently have an Antec 500W that is two years old)
Case - I want CoolerMaster HAF 932 or Thermaltake Chaser MK-1 (Whichever is cheaper)
When deciding PSU's read some professional reviews. AKA jonnyguru.com and hardwaresecrets.com There are other good PSU review sites but those are basically the best. I'm assuming off your previous collection of parts you've got a DVD drive. If I'm wrong ~20 bucks.
Down to business.
i5-2500k-best price/performance. keep
Mobo: ASRock Extreme 3 Gen3
GPU: I would recommend any 560ti or above. EVGA, MSI, and a plethora of other companys make great GPU's. This is a great card for cooling and performance. http://www.newegg.com/Product/Product.aspx?Item=N82E168...
The difference in the vram isn't as noticeable now, but future games are going to take more. 2 gb isn't going to change your FPS much right now.
RAM: Both company's you listed are great. I have the G.Skill Ripjaws X series 1600mhz version, and love them. Don't pay for more than 1600 mhz, and below 1333 either. (IMHO)
Case: HAF 932 or 922, CM 690 II, Lian Li cases. There are tons of choices here...
PSU: Corsair 650 or 750 modular your's looks good too.
If you can fit it, people who have SSD's love them. Not needed though...
Now I'm sure somebody more helpful will come along but this will get the ball rolling.