(a) In addition to other powers conferred by the governing law, a trustee has exclusive authority, consistent with the trustee's duties under this act, to:
(i) Establish an administrative budget sufficient, subject to legislative approval, to perform the trustee's duties and, as appropriate and reasonable, draw upon assets of the retirement system to fund the budget;
(ii) Obtain by employment or contract the services necessary to exercise the trustee's powers and perform the trustee's duties, including actuarial, auditing, custodial, investment and legal services; and (iii) Procure and dispose of the goods and property necessary to exercise the trustee's powers and perform the trustee's duties.