Well, setup A will wipe the floor with setup B. But I think we need more info about your plans for gaming, especially. What resolution are you planning on playing at? What games do you want to play? What is your budget for CPU and GPU?
Can you provide more information about your setup? If you are playing at 1080p I say go with choice b and IMO you could stick with a 4670k with the 770 because an i5 and i7 will have almost identical performance in gaming. If you are going with a multimonitor setup I suggest going with the 760 sli. If you only have a single monitor now just go with the 770 and sli it later if you plan to play at higher resolution