Have to concur with you sir. There's nothing better for static pressure than those rebranded NIDEC SERVO fans. They are excellent for forcing air through a liquid cooling radiator and would probably work well here. They sell a huge range of fan speeds for this and are nowhere near as expensive as Noctua Industrial fans. You can find the lower speed ones here Search: gentle typhoon - FrozenCPU.com
It's been a long time since I've looked for radiator fans (high static pressure), but it seems they are being phased out.
