If you have just a few trees, probably something simple and easily obtainable for you, like Captan, is going to be your best bet. Depending on pest pressure, if you spray a couple times starting about a month before harvest, that should help a lot. For a stronger kick in a high pressure situation, you could add a product call Montery Fungus Fighter into the mix, but it’s probably not necessary.
There are a lot of different approaches to the material to use to combat a pest problem (e.g. Monolinia fructicola - the fungus that is causes brown rot) and how often, as well as when to spray. So I wouldn’t necessarily expect the same answer from two different growers. It depends on one’s goals, type of fruit, location, etc.
Here are a couple different approaches to spraying.