Thirty years on, the Church still haven't found what they're looking for...by Keith Gribbins...Wandering rock 'n' roll's backroads for decades, the four members of the Church have been quietly exploring the outer reaches of progressive pop music over 30 plus records. Known to '80s music nerds as the ethereal Australian rock band that spun the beautifully nebulous "Under the Milky Way," the Church have never stopped making increasingly excellent records. In fact, it's the band's quest that keeps them so cutting edge. "The thing with the Church is that we're always trying to…