Such performance guarantee may be in the form of cash, certified check, negotiable securities, a performance bond issued by a bonding company or security company and approved by the Township Council or any other type of security acceptable to and approved by the Township Attorney and Township Council, provided that at least 10% of the performance guarantee shall be in cash or certified check. The balance of the performance guarantee shall be in the form of cash, certified check, certificate of deposit, an irrevocable letter of credit (issued by a financial institution whose deposits are insured by the Federal Savings and Loan Insurance Corporation or the Federal Deposit Insurance Corporation) or a bond issued by a surety or bonding company authorized to do business in New Jersey; provided, however, that all rights, including the right to interest with dividends, shall be assigned to the Township in a form of assignment acceptable to the Township Attorney for the period of the bond and that the principal amount of the passbook or certificate of deposit, together with interest, shall be returned to the developer upon completion of the bonded improvements or, in the event of default, both interest and principal shall be used by and for the benefit of the Township in the completion of said improvements.