Regardless of ability to hover an LT-40, I would go with a 50 sized OS, Irvine, or Magnum etc. As stated above, this is a big plane and the extra power comes in handy during that period leading up to plane 2 and if you go ahead and get the bigger engine it will be much more versitile when it comes time to put it in another plane. I have the LT-40 and I started with a 46LA (far less power than a FX) which is just enough to fly the plane. I also have an assortment of 50 sized engines and if I were starting over again I would skip the 46 size and go toward the more versitile 50s. More power = more fun later on. Ability to hover anything = many hours of practice + a few crashes.