As a fellow newcomer to the pattern world (I have a very experienced mentor) I am flying a GP Venus 40 with too large an engine (magnum 92 2-stroke APC 15x8). Have also flown that sized plane with a Magnum 52 2-stroke. The current configuration is straight and level with 30% throttle, but the vertical is unlimited. Took about an ounce at the tail plus some taller gear for the larger prop (and my inxperience).
Have fun
mike