The chairman of the Board, in accordance with rules agreed upon by the Board, shall appoint and fix the compensation of a full-time executive director and such other personnel as may be necessary to enable the Board to carry out its functions, without regard to the provisions of title 5 governing appointments in the competitive service, and without regard to the provisions of chapter 51 and subchapter III of chapter 53 of such title relating to classification and General Schedule pay rates, except that no rate of pay fixed under this subsection may exceed the equivalent of that payable for a position at level V of the Executive Schedule under section
5316 of title
5.