That z170 board isn't much of a use, unless you want it's features. And for PSU,that's an overkill unit even for 2 r9 380s , and it's better to have one single powerful GPU, for 1080p r9 390 was perfect. I5 6500 will keep up for 4-5 years easily.
no i dont need sli.maybe crossfire.i dont need os and monitor is full hd
A single r9 390 is good enough for 1080p for 2-3 years or so. Crossfire won't be required for 1080p + for r9 390 CFx you'd need a bigger PSU,and a motherboard that will support CFx which all will hit your budget, in 850$ a r9 390 with skylake i5 is good option,for 1080p.
That z170 board isn't much of a use, unless you want it's features. And for PSU,that's an overkill unit even for 2 r9 380s , and it's better to have one single powerful GPU, for 1080p r9 390 was perfect. I5 6500 will keep up for 4-5 years easily.