I currently have an i7-6700K in my build, it does the job for me to stream, record and play games at "Ultra" settings for GTA V at 144 fps (above) (I have a 144Hz monitor and I don't want my god to go under it). I am planning to change the CPU to either i5-7600K or i7-7700K, but I want my game to be at least 144fps at ultra settings while streaming and recording at 60fps.
Current build excl. the CPU:
GTX 1060
16GB RAM