Everyone, thank you so much for the terrific information.

Looking at the fans, I'm trying to finds ones that I'm able to purchase locally in Australia or have shipped. I also need 240V.

Would any of these do the job?

http://www.hydroexperts.com.au/Can-F...eed-Mixed-Flow
http://www.hydroexperts.com.au/Can-F...M-Plastic-Body
http://www.hydroexperts.com.au/Centr...-Carbon-Filter
http://www.hydroexperts.com.au/EP-FM...0W-78dBA-1.13A

And then something like this for the duct on the gantry??
http://www.hydroexperts.com.au/Blaub...M-Wall-Bracket

Thanks again guys, really appreciate it!