RE: Goldberg Yak 54 Engine choice
I'd go with a little more oomph that the Saito 180. The Brison 2.4 flies the plane GREAT, turning a 20x8 at about 7200 RPM. This is roughly equivalent to a Moki 1.80 which would also be a good choice. These would both be great 3D choices depending on whether you wanted to go glow or gas.