Need super quiet exhaust fan

Rather than going to a big box retailer and getting the best they have, check with your local plumbing supply shop. As a contractor that's were I go to get the super quiet models. Of course a remote motor is the ideal solution, as has already been mentioned.

The quietest solution is to put the fan on the roof (one storey) or on an exterior side wall (if there are floors above you) and connect a duct to the equipment room ceiling.

Regardless how you decide to do it, you also need to think about where the makeup air is coming from. If it's coming under the equipment room door (undercut) it could have a lot of dust in it. Better to install a "transfer grill" and filter, in the door or interior partition wall of the equipment room.

Nsgarch's solution is clearly a better mousetrap. Outside of that, Wpines is right. Panasonic is the way to go. For a ceiling mounted fan, they are spooky quiet.

Thanks guys. I like Nsgarch solution.

Again, Nsgarch is correct.
Don't use a metal duct hose to avoid more vibration.
Try www.build.com to find silent fans