The plan may include provisions for the modification of the existing contracts of the taxing district as evidenced by its bonds or otherwise. Such plan may adapt or alter the procedures provided by the statutes of Colorado for the levy, certification, and collection of general taxes to conform to the provisions of the court approved plan of adjustment, in accordance with federal bankruptcy law; except that nothing in this part 14 shall be construed to impair the rights of persons who have purchased property at tax sale. If the court approved plan provides for the issuance of new obligations of such taxing district for delivery to the creditors of the taxing district in exchange for outstanding obligations of such taxing district, such new obligations may be issued on the terms or conditions found in the plan of adjustment, regardless of any contrary state statute. Nothing in this part 14 shall impair the claims which creditors may have against persons who are not subject to jurisdiction of the court pursuant to chapter 9 of title 11, U.S.C. Any such plan proposed may provide for payments to creditors on terms and conditions which differ from the original contract if the present value of the total payments under the provisions of the plan do not exceed the present value of the total payments under the original contract.