Model Alternative Publicly Accountable Schools Act of 2003 - Authorizes appropriations for: (1) public transformation schools in the District of Columbia to expand opportunities for low-income District parents to enroll their children in higher-performing schools, and to fund the additional services necessary to achieve continued improvements in the performance of such students; and (2) the Direct Loan Fund for Charter School Improvement, to be used to expand opportunities for District students to attend charter schools in the District.