Tony, OS 20LA? Never saw one of those. They are not (yet?) available in the USA.

Steve, A lot depends on how proficient you are at building. Some people (most?) get so attached to their planes that they are afraid of crashing them. If that is not your case, by all means go with the Brodak Tomahawk and the LA 25-S.

You might also consider an RTF or a foamie to learn the pattern on, while you are building the Tomahawk.

The LA 25 is a well-liked engine.

George