Hi,
I think that I would go for a smaller return pump (say Iwaki 55RLT 1140GPH @ 0' Headpressure) and use a couple of Tunze streams (basically really big powerheads).
These pumps aren't cheap, so I'd try to get them used. The nice thing about the Tunze pumps is that they are energy efficient and move a ton of water. The bad thing is that they are physically huge and are expensive especially if you add all the gizmos like wavemakers, night sensors, etc.
If you find that you still don't have enough oomph, the Iwaki is a nice pressure rated pump so you could hook up a couple of "eductors" or "penductors" to them to increase the flow. Here is a very good thread on eductors:
http://www.reefcentral.com/forums/sh...hreadid=372881
Hope that helps. If you have any more questions, just ask.
Opps, I didn't see you wanted a quiet pump. If that is the case, I would go with a CSL T3 or T4 pump (now known as Posiden). They are ultra quiet pumps since the don't have a fan to cool the motor. However, they do put heat into the water as that is how they are cooled. A T3 is pressure rated whereas a T4 is not.