426 CFM? That's a LOT. I would say it's far too much.An 8" trunk that branches via a Y to two 6" branches should suffice. If this is through the basement, then pull colder air from the office and br and blow it into the stove room. The axial fan can be suspended off of rubber or noise isolating mounts, though there are good ones that are quite quiet at a reduced speed producing 200 cfm. Look for their sone or db rating if this is a concern.
And that much air will create a lot of noise, even if not from the motor itself. 42 dBA motor
I use this one:
Sufficient to "heat my home" (push enough BTUS from the basement up the stairs by depositing the cold air on the basement floor)
188 CFM (unloaded; so I have much less due to the 18 ft or so ducting); 39 dBA motor (so half the sound).