For training, The prop I've found seems to be an overall good prop and the one I now recommend for .46 size engines on trainers is the Hobbico NextStar prop. It's an 11 X 5 and holds up as good if not better than any other 11 X 5 prop. The red tips are nice at idle for a beginner to see, and the seem to cost a bit less than other props.

Hogflyer