The engine size would depend on how you want the plane to fly, ie, scale like or very fast (which they aren't in real life). Also, be sure that the recommended prop for the engine that you choose will give you adequate ground clearance. 4-stroke engines sound better since they aren't screaming like a 2-stroke. Remember lower pitch props will give you some dynamic braking when you throttle back and a lower top speed, but they will also give more thrust than a higher pitch prop.

The T-34 was based on the Beechcraft convential-tailed Bonanza.