What can you find from these brands in your budget.
Super Flower
Seasonic
Corsair
AIO?? I personally would not, but I don't know about your fear of temperatures, your feelings about cooler maintenance, your sensitivity to noise, the airflow characteristics of your case, your willingness to experiment, etc, etc, etc.
Obviously......if temperatures are your only concern, then you spend your last dollar on reducing temperatures to the lowest possible degree without regard to any other issue. You may think that is wise or stupid. Personal choice.
You may be panic-stricken if CPU temps are 70. You may be totally indifferent if CPU temps are 85. I have no idea.
Intel CPUs throttle by design. That may be meaningless to you. I don't know.