This is the motor they used in the 3d build. Which is close to what you have listed and will be more than enough for the duster.
http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=26820&aff=247441
Electric motors are kind of hard to get the hang of when picking them out. I always recomend going with what is suggested for the build and adjust from there.
Remember the high kvs spin smaller props fast and the low kvs spin larger props slow, when you need torque like in 3d use lower kv and when you want speed with less torque high kv.
Also keep in mind the number of battery cells. You can run a motor that is 1550 kv with a 2s battery and a 8x6 prop, then switch battery to a 3s and run a 7x4 prop with out any damage to the motor but run the 8x6 prop on the 3s and you may draw too many amps and burn it out.
I hope that doesnt confuse you.
I shop at
http://www.headsuphobby.com/main.sc
They list their motors by size and have a suggested plane weight listed along with suggested props and ESC's.
That helps when scratch building to get a proper size motor or at least a better idea of what to get.
I am sure you have watched the build videos of the planes, I have included the suggested componets list for the FT3D below.
Equipment used in this build:
NTM Prop Drive Series 28-26A 1200kv / 250w
Hextronic 9 Gram Servo
TURNIGY Plush 25amp Speed Controller
FT Firewall
FT Control horns
1 mm piano wire (push rods)
3D Hobby Shop motor:
Omega 72g Brushless Outrunner
Additional/Alternate components:
Suppo 2208/14 1450kv Brushless Motor (Park 370 equiv.)
APC-style Electric Propeller - 8x4E
Suppo 18A Brushless ESC
Suppo SP-90 9g Micro Servo
LazerToyz motor/power pack:
SWAPPABLE POWER/ELECTRONICS PACK "THE BEEF"
"THE BEEF" (Motor only) GT2210/11 55G
So any questions fire away!
AND Welcome to the forum!