Good fans are expensive. Don't be surprise to see your total price of 4 good fans to be more than 60 bucks. They do have 3-4 times longer durability/life expectancy than the cheap sleeves bearing fans you can find for 5-6 bucks each. The review linked doesn't have the most uptodate fans, especially very good one such as Scythe Gentle Typhoon, Noctua or Cougar Vortex.
If money is not a problem, the Scythe Gentle Typhoon is the best fan to get, they come with variable RPM from 600 to over 2000, air flow and noise of course will go up as you select the higher RPM fans. If you want noise level to be less than 30, 1850 RPM Gentle Typhoon should move a lot of air and is very quiet.
Noctua fan is equally good and is equally expensive as the Gentle Typhoon, they just have the red brownish color.
Cougar Vortex 12 is another very high quality 120mm fan, moves a lot of air (60-70 cfm at 1000 - 1200 RPM) and is extremely quiet (<20).
These 3 fans are expensive (costs more than 16 bucks each, some can go as high as 18-19). Fortunately, newegg is having a sale on the Cougar Vortex fans atm. You can buy them for 9 bucks each instead of 15 bucks. If you are fast, you may be able to get some.
Here are some links:
Cougar Vortex 12HP with pulse modulation (allow for fan speed adjustment without a fan controller) $16.99 Apply promo code EMCNDHH63 (-$5.00) = $11.99
Spec: HydroDynamic (Fluid) bearing, RPM 800-1500, Max Airflow: 70 CFM, Noise: 17.9 dB, 4 pin connector, Life Expectancy: 300,000 hours
http://www.newegg.com/Product/Product.aspx?Item=N82E16835553002
or
Cougar Vortex 12H without pulse modulation (need a fan controller of Asus motherboard Fax expert to adjust speed) $8.99
Spec: HydroDynamic (Fluid) bearing, RPM 1200, Max Airflow: 60 CFM, Noise: 17.7 dB, 3 pin connector, Life Expectancy: 300,000 hours
Orange color:
http://www.newegg.com/Product/Product.aspx?Item=N82E16835553001
Black color:
http://www.newegg.com/Product/Product.aspx?Item=N82E16835553005 $9.99
Not on sale:
Noctua NFP12 $26.99
Spec: SSO (Self Stabilizing Oil) Pressure Bearing, RPM: 1300, max Airflow: 54.6 CFM, Noise: 19.8 dB, 3 pin connector, Life expectancy: Not listed
http://www.newegg.com/Product/Product.aspx?Item=N82E16835608004
Scythe Gentle Typhoon $18.84
Spec: Ball Bearing, RPM: 1850rpm, Noise: 28dba, Max Air Flow 58.3cfm
http://www.amazon.com/Scythe-Gentle-Typhoon-850rpm-58-3cfm/dp/B001Q6RUVO/ref=pd_cp_pc_0