I just installed two NF-A14 FLX in my case. The change in cooling performance between the Noctua fans and the old Cougar Turbines I had is tremendous.
You case has two 120mm fan spots, so you can get the smaller NF-S12 FLX fan
which you can order as a two-pack
. It seems quiet and powerful, which is always a good combo.
If you're looking for a slightly lower-cost option, then the Cougar Dual-X
fans are pretty nice. Cougar makes them with nice LEDs in different color options; supposedly there is a smoky black option too.
Finally, if you're looking for the best cheap option, then Yate-Loons
are the way to go. The Loons come in low, medium, and high speed models.