(FORTUNE Magazine) – ''The flash of the 1980s is gone. Corporations want speakers with substance and ethics, or at least speakers who are not tainted.'' So says Don Epstein, president of Greater Talent Network, a New York City booking agency for some of the hot 1990s speechifiers. Adds William Leigh, head of the Leigh Bureau in Princeton, New Jersey: ''The trend is for serious, specific information rather than rah-rah, good-feeling generalisms.'' Thus the ongoing success of authors Tom Wolfe, John Naisbitt, and Michael Lewis -- and, maybe, the seeming rebirth of onetime presidential hopeful Walter Mondale. Education is an increasingly popular topic. Jaime Escalante, who teaches high school math in Los Angeles' El Barrio, is booked solid every weekend. His fee: an estimated $10,000. Out of favor: supply-side economist Arthur Laffer. Hardy annuals include Henry Kissinger. Says someone else's agent of the former Secretary of State: ''He should have lost his appeal. He says almost the same thing every time.'' Still, Kissinger gets an estimated $25,000 a pop. See below for a sampling of other speakers -- including Peggy Noonan, former White House speech writer -- and their agents' top asking prices. Book ahead. Lou Holtz, coach of Notre Dame's football team (some $20,000 a speech), needs a year's notice. - K.B.