Is it permissible to deal with a Druze person who works in a contracting company, and to provide him with technicians or building materials in exchange for money?

The Druze are an infidel, esoteric sect. It is permissible to deal with peaceful infidels and to work with them in permissible activities. Taking money in exchange for guiding people to technicians and contractors is a form of permissible brokerage. However, if harm is feared from dealing with infidels, then it is not permissible, due to the hadith: "There should be no harm nor reciprocal harm."