you are fine for 1080p. Because the rx480 is as good as a 970 . A 970 can max out all games at 1080p with 50 fps. So you should be fine. But I heart rx480 has thermal issues .wait for the Asus gigabyte and msi to make new versions of rx480 in order to have better temps. If you can't wait go for the 970. Hope this helped.
Don't go with the Reference RX480, get a custom board, like PowerColor Red Devil or Sapphire Nitro. Red Devil has been getting very good feedback, much quieter than Sapphire and less power usage.