WASHINGTON - Rebounding from the failed nomination of Harriet Miers to the Supreme Court, President Bush is poised to select between two of the nation's leading conservative federal appeals court judges--both experienced jurists with deep backgrounds in constitutional law--for what promises to be a bruising Senate confirmation battle. With an announcement expected Sunday or Monday, administration officials have narrowed the focus to Judges Samuel Alito of New Jersey and J. Michael Luttig of Virginia, sources involved in the process said.