Im looking to add two 140mm fans to my fractal r4. I've tried the corsair af140s but they have coil whine and are louder than the stock fractal fans at the same speeds by a good amount. Very disappointing fans. The fractals arent bad at 7v if only the motor was quieter...

Being canadian selection here isnt great but from what we do have im considering the bequiet silent wings 2 and the noctua nf-a14 uln or flx. Problem is these fans cant be returned only exchanged if theres a problem so i really need to choose wisely. the bequiets also run at a $10 premium over the already expensive noctua.

Between the two which is the better buy?

Also how loud is the noctua nf-a14 flx using the ULN adapter compared to the nf-a14 uln version of the fan. With the adapter it's still 100rpm faster than the nf-a14 uln but it would be nice to have the option to crank the fan up a bit on really hot days. I'm just worried even using the lowest speed adapter it'll be too noisy during silent nights but if these fans are as quiet as some say maybe....

Side question. Are the arctic cooling f14 fans any good?