Air cooling will be fine for any of the processors, although I'd want to get a high-end version (not the stock AMD cooler) for the 3600X if you do happen to get that CPU. Otherwise, the stock cooler will be good enough.
For the power supply, it's better to get at least a bronze-rated model from a reputable company. (Cooler Master is fine.) 400W should be enough, even if Nvidia recommends a 450W PSU for a 1660. The calculators I tried all said 400W would cover all the hardware you listed. Just be aware that if you decide to upgrade at some point, you might need to get a new PSU as well, depending on the component being upgraded.
