I would say, scratch the NF7-S, unless you are planning on adding SATA drives later. and get the far cheaper NF7.
You still get the advantage of the better onboard audio.
The issue with QTec Powersupplies, is that they are not high quality i.e. they do not provide high tolerances, or stable voltages, and therefore even high-voltage QTecs are not as good for your system as low voltage Antecs...