Which GPU should I get?

[HeyRusty]

I'm custom building a new gaming PC, but I don't know a lot about it. My budget is £1000-£1400, and the 'main' specs so far are these:

Intel i5-4670k Quad Core CPU
Gigabyte Z87X-SLi ATX
8GB Kingston Hyper-X Genesis RAM (2x4GB Sticks)
Corsair 650W CS Modular 80 Plus Gold
This is where I'm unsure; I'm only a casual gamer, and the only games I'll play are Rust, BF3 & BF4, DayZ Standalone and maybe Titanfall - I don't know whether I should get the GTX 780 or GTX 780 Ti - Like I said I'm only a casual gamer so I don't need to record with my system - Help?

 

[NiNJaOwNeD]

Get the GTX 780 ti, it will last longer when games get better graphics.