you may not need these but i ordered the following parts from
http://www.allerc.com/
i think you could use tha same nacelles you have and remove the motors and fans turn the motor around, use a piece of bass wood or poplar or med or hard balsa or even hard foam ( maybe from the box the plane came from) and make those brackets that you see on the diagram for the mods inside the rear of the nacelle, all you really have to buy is the prop adapter and props i would think
(i ordered 2 sizes here because below as i didnt know which was the right size)
2 x ELECTRIC POWER HEAT SINK FOR 380/400 MOTOR - EHS-400 (EHS-400) = $4.00
2 x ELECTRIC POWER HEAT SINK FOR 370 MOTOR - EHS-300 (EHS-300) = $3.50
1 x GWS A10 EDF 55 NACELLE KIT - UNPAINTED (A10-FAS7-1) = $12.00
good luck if you try it