My PC will have a core i5-4690K, and I will hopefully be able to overclock it to above 4GHz. 8GB DDR3-1600MHz. Going to be using either Mint or a fork of Ubuntu. I will not have a GPU for a while, so I am wondering if the iGPU on the core i5-4690K will be enough to run dolphin. I will be playing Super Mario Sunshine and similar 1st party GameCube games and hope to be able to run full speed it at at least 2x resolution.
The Haswell refresh is actually well suited for overclocking, so unlike the i5-4670K, you won't really have to worry about getting one of the "bad" lots. The HD 4600 should actually be fine for just about any game at 2x IR, and number of games will let you push it to 3x IR, and even 4x IR in some. For most any game, all you'll need to do is OC if you're having any speed issues. Just be sure to use the latest development revisions of Dolphin (not the stable builds). The latest versions are very fast in comparison to 4.0.2, though this might mean building from source depending on your version of Ubuntu or what kind of repos you have available.
the i5-4690K is terrific, based on my personal experience. I have the locked version of the 4690 and it runs great.