The motherboard for the more fan headers so the two fans can be connected to it and the better audiochip.
The psu for better quality,but the EVGA G3 550watt isn't much more so a very good choice too. Chose this Bitfenix so it's getting mentioned too once in a while since a good psu.
There's also this case which is good but the m-atx board might look abit small in it. https://uk.pcpartpicker.com/product/2WkD4D/corsair-case-300rwindowed