The Panaflo L1BX is still a good fan - jab-tech.com has them. If you have room for a 80x38, sidewindercomputers.com usually has some Delta 3-blade fans - but you'd have to turn 'em down a bit to hit the noise/airflow specs you set. The Sharkoon golf ball fans are a nice and quiet tech, but IDK where you'd find any except LED here (but you could cut the LED leads).
.bh.