What all this kind of boils down to is for you to make a choice on what kind of flying your going to do with a specific plane, engine for which you will need the appropriate prop.

One the average most 3d'r's use a prop of less pitch. Warbirds and general all around planes install whatever and those who want speed go with a higher pitch prop.

So when you come on here and ask "what kind of prop should I use with this engine?" before this question can be logically answered, we need to know what kind of plane and size and whatkind of flying you want to do with it.