7PM This episode's headline: The Future of SALT II; Spotlighting Special Prosecutors; Steroids and Sports; A Letter from Texas. The guests include In Washington: PAUL NITZE, Arms Control Advisor; JOHN BANZHAF, George Washington University; In New York: ARTHUR CHRISTY, Former Special Prosecutor; In Columbus: Rep. THOMAS KINDNESS, Republican, Ohio; REPORTS FROM NEWSHOUR CORRESPONDENTS: JUNE CROSS, in Washington; TOM BEARDEN, in California; MOLLY IVINS (Dallas Times-Herald), in Texas. Byline: In New York: ROBERT MacNEIL, Executive Editor; In Washington: JIM LEHRER, Associate Editor