Go with the G5400.
The rx 570 is not exactly a power house so you will need to play with game settings to see what you can get.
I am currently looking to get a brand new gaming pc
Here is what im looking at:
Gigabyte h310m s2h
Kingstone HyperX Fury 2x4gb ddr4
Rx 570 expedition oc 4gb
Silverstone et450 450w psu
Seagate barracuda 500gb hdd
Phanteks p300 tempered glass case
I am aiming to play fortnite at high or epic settings and i just need to know if this pc will do the trick!
PS. Im on a budget and i cant really afford the 1060 (the rx570 is on discount)
And should i get the g5400 gold or stay with the g4560