Yes the 4670K is a great choice for gaming. The run hot so you need a good cooler to overclock, but yes it's a good choice. I recommend either a cooler master 212 EVO, Noctua DH14, or a Corsair H100i.
The 4690k is "in stock" and shipping already... That's what I would do if I was you. You could get an Asus Z97 equal, if you are set on Asus.