Just a note on the OS LA series of engines. They run well, and are easy to work with for a beginner. But they are, in fact, under powered compared to most other engines in the same size. However, all of the .40 trainers that I've seen will fly just fine on the .40LA, it's plenty for learning and basic acrobatics. You just don't have the extra power that the other engines give you, which may limit some types of acrobatics later on, as you won't have the power for extended up lines.