Agree with geofelt. Also within the Noctua line, look closely at their IndustrialPPC models. They deliver much more air flow than regular models, use a bit more power and generate more noise at top speed than their regular models. The don't create the huge air flow of the Delta units you mentioned, but I think they do give you all the max airflow you would need.
I think you may be confused on fan power. It may be specified in terms of Amps or Watts at full speed, or both. Full speed means always that the fan is supplied with 12 VDC. Watts = Amps x Volts. So, for example, a fan that consumes 1.0 A current at full speed is consuming 12 W power; a fan using 20 W power at 12 VDC is consuming 20/12 = 1.67 A current. Most mobo fan headers can supply up to 1.0 A current max to all fans connected to that header, so you could not connect a 20W fan to one. But a powered fan HUB often can handle that on one output port, and most can handle several fans like that connected to separate output ports.
A fan HUB is not the same as a third-party Fan Controller module you mount in the front panel. It is a smaller box mounted inside your case with two cable connections: one to a power output from the PSU, and another to a mobo SYS_FAN or CHA_FAN header. The latter cable picks up from the header the PWM signal for the new 4-pin fans and that is distributed to the fans on the Hub. So the mobo header MUST be configured to use the new PWM Mode of fan control, and not the older Voltage Control Mode (aka DC Mode). Likewise, the fans you use with this MUST be of the new 4-pin PWM type, not the older 3-pin type.
There's another important limit for a fan Hub OR Controllers box you need to keep in mind with your plans, depending on how you finalize. One common source of power for the unit is a SATA power output connector from the PSU. BUT the standard SATA connector has a limit of max 4.5 A total current to the connected device, and you are talking about several fans with up to 1.67 A max current. The other power option for the Hub or Controller is via a 4-pin Molex output from the PSU. IF that is part of the Hub's design, that type of connector CAN supply well over 10 A total current, so it would work IF you choose those Delta fans and need that much power.