A book that left burn marks on night tables across continents, ''Lovers And Gamblers ''has become a Collins classic. It features two of her most memorable characters: Al King, the rock-and-roll superstud who is everything any sex-crazed groupie ever imagined her hero to be; and Dallas, the beauty queen whose sky-high ambitions stem from a sordid secret--the type that tabloids tingle to tell. Together, they''re on a wild ride from London to New York, from Hollywood to Rio and the steaming jungles of the Amazon--where all their dreams and nightmares are about to come true.