R9 390 over the 970. It will be more than enough for 1080p.

Always get the best single graphics card over dual graphics cards (Unless you get into Titan territory, then get 980/980 Ti SLI over 1 Titan)

look even a 960 (possibly a 950) are fine for 1080p.

For AMD I cant talk

GTX 970 would do just fine if you are mainly up for 1080p games and pay no more. I heard from a friend his zotac 970 can also run at 1440p at a very playable level

Ho with GTX 970 its stable and good AMD graphics are hot and are not stable choice

Get a GTX 970. If u can get a 970ti or ti x. You will be happy in how well the graphics do!

I've got an Asus GTX 970 and Fallout 4 or GTA V run great at 1080p and at 15c cooler than my last AMD card