If you don't like the Ninja, you might consider another of the high-end coolers. Thermalright's Ultra 120 sounds like a good fit.
I've never actually used a Noctua, but they're supposed to be very, very close to the Nexus fans. You can find a comparison
at SPCR. The Nexus is a lower-speed YL, possibly with a little more quality control. IMO, the YL wins, because it's about 1/4 the price. Buy a bunch and cherry pick your own. Plus, silencing tends to be an incremental process, and the YLs are plenty good enough to start out.