Brand names, I'd say starting at $200 and going up.
A straight 1080 can drive 4K easily. Hell a 1070 CAN. Yea, a TI or Titan does better here.
That's the only time I recommend 1080's. Few games are natively 4K so anyone chasing that monkey is an early adopter. I am an early adopter is many things, but I do NOT chase the monkey in Video Cards. My current 1070 was actually the first time I ever bought latest gen available actually. Previously I'd buy a gen behind.
My BFF has that same 1070 card I have but with a 144 4K wide ass monitor... Doom looks better on his even though it isn't truly 4K.
I wish I had enough friends that played one game with me. Can I frag wth you Unob if I get GR? lol