From my own experience I haven't noticed much of a difference from different fans. But then again I don't have much experience with it so you might want to wait for more answers.
I have had my PC for about two years now, in it I have the original NZXT fans, Noctua fans, and BitFenix fans. I've had the NZXT fans the whole time and they are quiet and effective and still going strong. the Noctua's are new but extremely quiet and effective at low speeds, but pricey. And contrary to what I've heard from many, the BitFenix are very effective and very quiet, plus super cheap.
My advice is try different things, make sure you can return them if you don't like them. Just FYI, I use a fan controller so that is mainly responsible for the low noise, just try to find a way to keep the RPMs down some how. I find that in terms of airflow 50% speed is almost as good as 100%, but 25% is crap airflow but whisper quiet.
Noctuas anti-vibration pads are brilliant though if you suffer vibrations noises in the case.
Good luck.