Ended up going with the EVGA SuperNOVA 650 P2 after reading this review:
http://www.tomshardware.com/reviews/evga-supernova-650-p2-power-supply,4364.html

Two things that stood out:

- "this PSU is almost exclusively silent; its noise output is actually closer to that of a passive unit. If you want to build the quietest possible system and don't want to rely on a fanless supply, EVGA's SuperNOVA 650 P2 should be your choice."
- Low ripple.

Will use this PSU until the inevitable purchase of an LPSU comes to fruition.