Some of the Enermax are very good .... with low noise a factor such a priority may I suggest:
Phantekls Enthoo Pro - $100 (comes with two fans)
http://www.newegg.com/Product/Product.aspx?Item=N82E16811854003
Phanteks 140SP - $9.99 x 3
http://www.newegg.com/Product/Product.aspx?Item=N82E16835709023
So you can get the "Best Case if 2014" along with your 5 fans for just $5 more than ya expected to spend on fans.
Best fans on the market ... and yes better than Noctua's ...
They run 3c cooler while Nocs run 25% faster rpm.
http://www.overclockersclub.com/reviews/phenteks_f140/3.htm
They have the best performance / noise ratio in silentpcreview.com's testing ... again topping the Noc's
Silentpcreview.com Fan Rankings
http://www.silentpcreview.com/article1361-page5.html
Performance / Noise Ratio Standings - 140 mm
Antec TwoCool 140*
Phanteks PH-F140HP/TS
Scythe Kaze Maru 2 Adj. VR
(Slip Stream 140)
Noctua NF-A14 FLX
Noctua NF-A15 PWM
Corsair AF140 Quiet
Scythe Slip Stream 140XT-MP
Scythe Slip Stream 140XT-M
Scythe GlideStream 140-M
Noctua NF-P14 FLX
Antec TrueQuiet 140
bequiet! Silent Wings 2 140
Thermalright TR-TY150
Xigmatek XAF-F1453
Xigmatek XLF-F1453
* Fan has the PWM clicking sound
Performance / Noise Ratio Standings - 120 mm
Noiseblocker B12-2
Scythe Gentle Typhoon AP12
Scythe Slip Stream 120-M
Noiseblocker M12-S1
Corsair AF120 Quiet
Scythe GlideStream 120-LM
Corsair AF120 Performance
Scythe Gentle Typhoon AP14
Scythe GlideStream 120-MP
Nexus Real Silent
Noiseblocker B12-PS
Corsair SP120 Quiet
bequiet! Silent Wings 2 120
Noiseblocker M12-S2
Scythe Grand Flex-SH-P
Scythe Grand Flex-M
Noiseblocker M12-P
GELID Wing 12
Antec TrueQuiet 120
Antec TrueQuiet 120 Pro
Antec TwoCool 120
SilverStone AP123
The Enermax wasn't tested but having both, I'd put them in the same class as the Corsairs.