Regarding power requirements, the alternatives to a GTX 1660 vary depending on the card. For example, the Radeon RX 590 requires up to 225 watts of power, the RTX 2060 Super needs up to 175 watts, and an RTX 2070 needs up to 215 watts.
It’s important to note that these are peak power draw figures, and your actual usage will be lower than these figures most of the time.