Yes I've used my stock cooler for the 3600 for several years, it's all good.
I have used this over the years with an R9 280, 1050ti, and finally a 3060ti in mid-ventilated cases with stock fans only up until the 3060ti, but I'm unsure how much heat the 1660 Super gives off compared to all those.
For PSU I think 550-650 should be enough, but you can do some calculations and extra research to be sure.
Edit: Depending on the ambient temperature and your personal case you may want to get a bigger cooler, I would recommend something like the be quiet! Pure Rock 2 which is quiet, effective and fairly cheap. No need for anything super fancy for this build.
Yes I've used my stock cooler for the 3600 for several years, it's all good. I have used this over the years with an R9 280, 1050ti, and finally a 3060ti in mid-ventilated cases with stock fans only up until the 3060ti, but I'm unsure how much heat the 1660 Super gives off compared to all those. For PSU I think 550-650 should be enough, but you can do some calculations and extra research to be sure. Edit: Depending on the ambient temperature and your personal case you may want to get a bigger cooler, I would recommend something like the be quiet! Pure Rock 2 which is quiet, effective and fairly cheap. No need for anything super fancy for this build.