How much RAM should i get?

Hello, im getting a new pc system, with this specs:
Intel 4790 4GH
nvidia GTX 980 FTW ACX 2
an SSD drive

i thought of getting a compact mini-ITX corsair 250D but then i can only put a maximum of 16gb of ram. should it be enough? or do i need more? plus will 1600 hz RAM speed be enough?

im gonna use it for ue4 game developing for the oculus rift, 3ds max, sketchup, photoshop, sometimes all at once.

thanks for the help!

Hello, MATAN

Please note that some factors need to be taken into consideration when selecting hardware for Unreal Engine 4.

This should help you:

Good luck!