The 6000 RPM delta fan and the Ultra Sleek Vortex 14 are in totally different classes, it won't work.  Delta is doing 210+ CFM at max speed, the vortex only 98CFM.  There is almost nothing comparable to Delta fans on these things.

There's a fan called the Scythe Ultra Kaze that runs at 3000 RPM, pushes a ton of air and is slightly quieter, but it only works if u have the non-autotune S9 and can downclock the frequency a bit.