Any securities herein authorized to be issued shall bear such date or dates, shall be in such denomination or denominations, shall mature at such time or times but in no event exceeding forty years from their date or any shorter limitation herein provided, shall bear interest at a rate or rates not exceeding six percent per annum, which interest may be evidenced by one or two sets of coupons payable annually or semiannually, except that the first coupon or coupons appertaining to any security may represent interest for any period not in excess of one year, as may be prescribed by resolution or other instrument; and the securities and any coupons shall be payable in such medium of payment at any banking institution or such other place or places within or without the state, including but not limited to the office of the treasurer of the county in which the authority is located wholly or in part, as determined by the board, and the securities at the option of the board may be in one or more series, may be made subject to prior redemption in advance of maturity in such order or by lot or otherwise at such time or times without or with the payment of such premium or premiums not exceeding six percent of the principal amount of each security so redeemed, as determined by the board.