The .40 LA will be fine. It will require longer take off rolls and not fly into the wind as fast. The .46 LA does have a bit more power and would be my first choice for the budget minded. The .46 FX would be even better and possibly last longer. My son is currently flying an Avistar with a .46 LA that has seen at least 3 other trainers meet an untimly death, but the .46 just keeps on going! Good luck!!