Best propane gas supplier will depend on your country, as different gas Companies operates differently in each country. Some Country import propane because of the absence of oil and gas fields in the country, while oil rich countries like Saudi Arabia process their oil and gas into products like propane, so the case of Saudi the dominant Company with respect to oil and gas is Saudi Aramco, in Brazil for example the top indigenous Company is Petrobras, so the list is endless depending on the country.