The Commission shall appoint a staff director, who shall be paid at a rate not to exceed the maximum rate of basic pay under section
5376 of title
5, and such professional and clerical personnel as may be reasonable and necessary to enable the Commission to carry out its duties under this subchapter 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, or any other provision of law, relating to the number, classification, and General Schedule rates.