You've had advice to hire a farm manager; and research roasting.

Nobody so far has mentioned the processing. Roasting is for roasteries; that's not really the farmer's business. But in most coffee-growing areas, the farmers organize into collectives, with shared processing facilities. A lot of the distinctive characters of coffees are the result of the way the cherries are processed. Since the collective's output is all mixed together, it's not single-estate; I assume that sales are handled by the collective, not by individual farmers.

Maybe there isn't a processing collective in your area; perhaps you could launch a processing facility, and encourage your neighbours to have a go.