The i5-4690K is the "updated" version of the i5-4670K with better thermals because people had complained of high temperatures. It's also cheaper.
Get an aftermarket cooler because its an unlocked processor meant for overclocking. If you don't want to overclock, I can revise your build so you can save some money there and spend more on the GPU.
For HDDs, I always go with Seagate Barracudas. They seem to have better performance than the WD HDDs I've seen.
The Rosewill Capstone 750W is a steal at $40. You'll have tough luck finding any PSU of its specifications that can compete at even $60.