Behind you, laying my corrupting hands upon your shoulders. Soon, you shall be an extension of me.
650W PSU just to be safe(you would be able to overclock your card if you're planning to). I've got the EVGA NEX650G, it's pretty decent, cerified as gold so you should be fine with the setup you're having. I'm running i7-4790k and GTX 970 off of it. Good luck!