PSU?

Check the specific power consumptions for each component. The CPU / GPU need the most, everything else is relatively small (though not neglibible).

I would say to expect at least something like 150W peaks for both the gpu & cpu, everything else should be withing another 100W range. Though irrelevant right now, sometimes you must take care the check whether the PSU can supply specific components with enough power (it might split the power in a manner that can't power your components). You won't have to worry about that until you get like 3 cards though, so as long as you get something 600W-ish or more you should be okay. Plenty of space to OC and stuff.

PSUs usually have their own cooling which suffices, most have a single med/low end 120mm fan. If you're talking about the whole PC .. dunno. Depending on what CPU heatsink you're getting (if any, as stock should be "okay") 1-2 for the CPU, depeding on what cooling you're getting for the gfx card (if any, as stock should be "okay", much like the cpu) 1-3, I would probs add 3-5 on the case, depending which one you're getting. I never really fancied NZXT, dunno anything about their air flow or fan positioning.

The rad itself is nothing more than a metal thing with lots of ribs. If anything uses power it's the pump and any fans attached to the rad