The Executive Budget Office and Revenue and Fiscal Affairs Office shall employ competent budget assistants and such special help as it may require to carry out the provisions of this chapter. It shall fix the compensation of such persons as it shall employ in this connection and cause such compensation, together with their necessary traveling expenses, to be paid out of the civil contingent fund. It shall call upon the State Department of Revenue for any information desired, and the State Department of Revenue shall furnish such information and shall be present at all hearings before the committees having charge of the appropriations in the Senate and House.