The board of trustees shall be empowered:
(a) To appoint a bank or banks or trust company or trust companies, or insurance company or insurance companies, to be designated as `corporate trustee' and to enter into and execute a trust agreement or agreements with such `corporate trustee', to provide for the investment and reinvestment of the assets of the trust fund in any type of investments that are legal for trust funds in the State of Michigan held for a city retirement system (or policemen and firemen retirement system, if more restrictive). Said agreement shall incorporate therein such other provisions (consistent with this Chapter 18) as may be deemed desirable by the board of trustees for the proper management of the trust fund and upon execution to convey and transfer to such corporate trustee any of the assets of the trust fund. The board of trustees shall be forever released and discharged from any responsibility or liability with respect to any assets which they may convey to such corporate trustee.
(b) To enter into agreements, contracts and other instruments for the deposit of funds with banks, trust companies or insurance companies or other institutions which accept and hold money on deposit, and to authorize such depositary to act as custodian of the funds, whether in cash or securities or other property, and to authorize such depositary or depositaries to convert, invest and reinvest funds, entirely or in part, into securities of any kind and nature whatsoever; to authorize withdrawals of moneys from such account or accounts, checks for such purposes shall be signed by any two of the officials authorized to sign the general fund checks, one of whom shall be the treasurer of the City of Inkster.