Agreed. Neither Corsair CX or Antec HCG is what I considered premium high quality PSU for expensive PC. They are mostly for budget user. You should look into reputable PSU like Rosewill Capstone, Seasonic Gold Rated PSU, etc.
Also, keep in mind that 3D gaming only works for games that support 3D in the first place. You are not going to see 3D effect on Wii emulation.
Dolphin supports 3D.
In most cases, i5 performs identical to i7 in gaming. The i7-4790K is a little bit of an exception because of the 0.5Ghz clock increase over the i5-4690K, and emulation gets respectable performance boosts from higher clock rates.
This might seem like a silly point to pick on.. but do you really need a DVD drive? After installing Windows (which can be done from USB) and motherboard drivers (which are better off downloaded from the official site in the first place), would you actually use it? If not, I'd put that $18 towards a better PSU (preferably gold rated).
Aside from that, the build looks fine to me. Personally I'd always make sure there's an SSD in the build, especially now that 120GB (what I consider the minimum for a fresh system) is so affordable these days (around the $75 mark).
It's only about $20, there's really no reason not to have one when it's this cheap. Plus if I ever want to put in a DVD to watch a movie, I can.
All GTX 970s support 3D, it's not a manufacturer specific feature, it's a Nvidia one.
You can just overclock with the i5 to match the i7, the difference is that the i7 has a feature called hyperthreading which isn't even used in games iirc.
I don't really want to overclock it (rather not take the risk). Is the MSi one really stronger than the EVGA one?