I have looked at doing this to my hog bipe, 8S pack with an outrunner... finding a power plant is not that difficult, the hard part is where to put the battery, with the electric setup you will probably want the battery fairly close to directly behind the firewall for balance... There is no convenient way I have yet found to make that area accessible to remove and charge the battery without taking off the wing. If you come up with a hatch system that works post it so it can be copied... it may be eaiser starting with a kit instead of a complete airframe.