I strongly recommend against cheap PSU units or actually purchasing without researching a bit first.
A lot of the units on the market have really bad voltage regulation, especially on the 3.3V and 12V rails along with bad ripple. Furthermore, a cheaper PSU is more likely to trip on an input load that supposedly matches the output (for example 600W wall draw instead of 600W delivered on the rails).
While it's generally true that with mild overclocking it will do 'fine', after all, the power supply must supply the motherboard, GPU and peripheral devices with clean power. I would not trust any components whose power load may spike on a cheap supply.
From the recommendations above I support the EVGA and RoseWill supplies, and I'd also add most SuperFlower and SeaSonic supplies you can get your hands on. FSP (previously known as Fortron) also have very decent units that do not come off as expensive.
Regarding power draw, @Brett Bergan's suggestion for 160W for the RAM is outlandish. DDR4 RAM (without a ridiculous overvolt) will rarely consume over 3-4W per module.
As for power supply, I would actually recommend a SeaSonic M12II 520 Bronze which is surprisingly cheap while still retaining full modularity and providing clean output.
520W will be more than enough for your system until you decide to push things to the limits, and those PSUs can be trusted.
I've pulled over 1100W from the wall on my 850W unit (SS-850AM, Bronze efficiency) which is a bit over it's rated output and still didn't even trigger it's OCP.