it might be possible for u large to buy a panaflow or papst fan in from Europe online maybe largo? what with the Euro Free trade zone, don't understand it personally down here in Oz but it might be possible.
With the fan u've specced, it's the enermax adjustable fan, very good actually I've got two 80MM's in my case, nice for adjusting to the levels u want to run at for your balance of sound over cooling, but...
how u going to run the pot (the twiddle knob is the technical term I think
) to the outside of the case? I was going to install one onto my PSU but I would've needed to find a way to route the twiddle knob to the outside of the case so I just stuck in a panaflow instead