Hi,
It depends of your budget but I will not recommend more than a GTX1080 with a i7 3770K under conditions that this CPU is overcloked.
Edit: I noticed that you can't OC the CPU with this motherboard. So I would recommend a GTX1070 or a GTX1070TI instead. You may can go for a 1080 but I fear the bottleneck as the CPU is not OC.
You should also upgrade your memory, a total of 16GB is recommended today, especially when playing with a high end Graphic Card.