Sorry I can't type Chinese while in Company

Which gentle typhoon I need to choose?

$18.79 Scythe Gentle Typhoon D1225C12B3AP-13 - Case fan - 120 mm
$22.79 Scythe Gentle Typhoon 120mm Case Fan- 1,850rpm, 28dba, 58.3cfm
$22.79 Scythe Gentle Typhoon 120mm Case Fan- 1450rpm, 21dba, 45.9cfm

I am considering of 1850rpm one, but not quite sure about it
Can anyone give me some advices? Thanks

My system right now contains H50 with 2x Scythe S-FLEX SFF21E / 120mm 1,200rpm Fan for the CPU, and on the top 3x Noctua NF-S12B FLX - Case fan - 120 mm. And 2 hardrive fans at front from the Cooler Master COSMOS 1100 case, it's a little bit noisy right now the temperature is about 36 for the i7 950.

Thank you