The State Treasurer may enter into such contracts and guarantee agreements as are necessary to operate the Student Investment Account with eligible lenders, financial institutions, institutions of higher education, income share agreement providers, individuals, corporations, and qualified income share agreement or loan origination and servicing organizations and with any governmental entity, including the Illinois Student Assistance Commission, and with any agency or instrumentality of the United States. The State Treasurer is authorized to establish specific criteria governing the eligibility of entities to participate in its programs, the making of income share agreements or education loans, provisions for default, the establishment of default reserve funds, the purchase of default insurance, the provision of prudent debt service reserves, and the furnishing by participating entities of such additional guarantees of the income share agreements or education loans as the State Treasurer shall determine.