UNSUNG HEROES OF ROCK 'N' ROLL by Nick Tosches (Harmony Books/Crown: $10; 276 pp.). Nick Tosches, whose meditation on Jerry Lee Lewis' excesses ("Hellfire") is perhaps rock's best biography, returns with a revised edition of his account of rock's most original, gaudy--and downright crazy--pioneers. For Tosches' taste, the crazier the better. Where else could you discover the exploits of Ming and Ling, the Chinese Hillbilly devils who did a rockabilly rave-up called "Eggroll Eatin' Mama"? Tosches may be a sucker for booze hounds and stylish rogues in sharkskin suits, but he writes with color, fervor and a cagy sense of history. Resurrecting blues shouter Wynonie Harris, Tosches celebrates all of his lurid excesses but reminds us of his impact on Elvis Presley, who copied his "pelvic jab-and-parry, the petulant curlings of his lip, the evangelical wavings of his arms and hands."