Pancake Fan(s) for ZC Fireplace Blower?

My BIS Nova blower is toast (screaching sound...maybe a spun bearing), so I'm considering replacement / upgrade options.

I have a larger transflow blower from Dayton/Grainger that puts out over twice the air as the standard blower (336CFM vs. 130CFM on factory blower). Only concern I have is noise, and perhaps sucking in smoke/ash when the door is open. Also need to rig up a mount, but lots of options for that...its wide open under the firebox.
This unit: http://www.grainger.com/Grainger/items/4C848

Another option I'm considering is axial pancake fans like used for cooling computers and control enclosures. These seem quieter than transflow blowers, and move quite a bit of air. Could gang together 3-4 fans and make quite a breeze. Something like this: http://www.grainger.com/Grainger/items/4WT47

Anyone tried a pancake fan inside a fireplace enclosure? Any other posts on this anyone can recall?

Thanks!

Now that I'm looking for these, I guess they are more commonly referred to as Muffin Fans.

Yup...considered that. Seems like a lot of other folks have changed blowers without issue though.

What kinds of risks and failure modes should I be considering? Sucking in smoke/ash when the door is open is all I can think of. Any other issues with higher-that-factory-spec airflow anyone can think of? I'll make sure any wiring in well protected and properly grounded.

I like running wires in BX metal casing for extra protection. I'm quite paranoid and will likely over do it from a safety standpoint...

After seeing how sloppy the wiring (small/thin wires, crimp connector fell off, temp switch spliced into power cord) was on the factory blower, I'm thinking I can only make it better.