is corsair rm850x is good psu?



in my country rm850x cheaper than rm850i about $27-30
here is my build: i3 6100 CPU (upgrade soon when i7 7th generation arrive), gigabyte ga-z170x gaming 7, asus strix rx 480 08g, ddr4 8 gb (upgrade soon 16gb), 2 hdd, 1 ssd.

I want 850 watt psu for future upgrade.

 


what about the other component? which better?
 


The rest of the components are the same. Equally good.
 


Thanks for advice, can you recommend how much wattage PSU do i need?