Looking to add a second GTX 780 to my build, looking for some tips.

MY current build:

Motherboard - Asus P8Z68-V/Gen3 LGA 1155
CPU - i5 -2500k
Memory - Corsair Vengance 16GB DDR3 1600mhz
Power - Corsair Enthusiast 850-Watt
Case - Cooler Master HAF922
Monitors - HP 2511x (LED 25 inch 1080p) & QNIX QX2710 (LED 27 inch 1440p primary gaming)
GPU - EVGA GeForce GTX780 Superclocked 3GB

I am looking into getting another GTX780 since it has dropped in price and nvidia is offering 3 free games with it. Though I do know I would have to upgrade my Motherboard and CPU(as a result of the MB upgrade) in order to accommodate 2 GTX780's. As you can see I have a 1440p monitor as my primary gamming monitor, and am looking into possibly getting 2 more of those over the next 6-9 months. Therefore, I am extremely interested in knowing if investing now for the additional games is worth it or if i should just wait and upgrade over time? (Game Deal)

P.S. I posted this in PC's forum section but it seems to be rather inactive.... So I cam here to this active and fair(usually) forum.