of whether a certification described under that paragraph is in effect with respect to the compensation of the category of employees or other personnel. (6) Consultation required The Chairman shall consult with the Director of the Office of Personnel Management in implementing this subsection, including in the determination of the amount of compensation with respect to each category of employees or other personnel. (7) Experts and consultants (A) In general Subject to subparagraph (B), the Chairman may— (i) obtain the services of experts and consultants in accordance with section 3109 of title 5, United States Code