There are some system/component considerations that are not obvious.
I ran an Alpha 6045U for a long time on my KR7A board. It is designed to suck air up through the pins.
I installed the 6045U on an 8RDA+ board. After installing an active NB cooler, I noticed an immediate increase of 1C - 2C in CPU temperatures. The heat expelled from the active NB cooler was being injected/sucked into the Alpha, raising CPU temp. Reversing the fan didn't cure the problem, since the cooling efficiency of the 6045 really is better with fan sucking.
I replaced the 6045U with a 900U and a 92mm fan, providing better cooling with acceptable fan noise. One benefit with the 900U/92mm fan combo is that there is an 'overlap' of the fan on two sides due to the non-square design of the 900U. That overlap produces a stream of air on the MOSFETs on one side and surface components and memory on the other side.
Hope this helps!