The officers of a commission shall consist of a chairman, vice-chairman, executive secretary, treasurer, and such other officers as the commission shall deem necessary or appropriate. The chairman and vice-chairman of a commission shall be elected by the commission from the membership thereof. The executive secretary shall be appointed as provided in Section 11-65-10. A commission may appoint the principal financial officer of the sponsoring municipality as the treasurer of such commission or it may appoint its executive secretary as treasurer and combine the duties of the two offices, or it may appoint and employ a treasurer as provided in Section 11-65-10.