[Army Air Corps]

Here are some good duct and fan combinations:

http://www.hobby-lobby.com/ductfan.htm


Here are some electric motors that would be appropriate:

http://www.hobby-lobby.com/brushless-motors.htm

You may also wish to use other motors like some of the potent Tamiya motors used in electric R/C racing.

[King Prout]

this one seems appropriate:

68mm rotor diameter, 72mm outside diameter of tube and 93mm dia. front fairing ring. The motor housing is 29mm inside diameter and fits 480’s and Mega Motors MM16152 and MM16153 Brushless 400’s.

WMF0013 Mini Fan 480 for 3.2mm Shaft Electric Motors ..... $ 53.50