Hi!
The OS LA 40 can swing many different props sizes. But a 10x6 is too small for the average high winged trainer (150-160cm in span).

A much better prop size is a 11x5, 11x6 or 12x4 APC or RAM prop. Do not use the white tipped MA props though!! Those are the worst props on the market performance/sound wise.
A 11x4 could be used but is not that suitable for a high winged trainer powered by an OS LA .40 engine at sea level. I use props that size on our clubs two trainer airplanes powered .28 two strokes.