RE: 45
If the plane ends up at the predicted weight of around 4 pounds, you want to have about 100-120 watts per pound to perform aerobatic maneuvers. For extreme 3D, you may want to go higher (150-200 watts per pound). I have the following power system for my Pilatus PC-6 that weight in at 93 oz (6.4 pounds).
Turnigy SK 42-40 750kv motor
Turnigy Plush 60 Amp ESC with BEC
11 x 8 Master Air Screw 3-blade prop
Flightmax 4S 5000mah Battery
15.55 Volts
37.63 Amps
585 Watts
9210 RPM
93 oz AUW
This setup would give you 146 watts per pound assuming your plane has an All Up Weight (AUW) of 4 pounds.
Good luck with the conversion....