American Idol judge Katy Perry, 39, announced this year how she thinks her time on the show is coming to an end. Now, former Idol winner and accomplished music artist Fantasia, 39, thinks she can fill the California Girls singer’s shoes. But, fans have all kinds of ideas for Katy’s “replacement.” Since American Idol season 16, Katy Perry has been on the judging panel alongside Lionel Richie and Luke Bryan. Who better to guide budding musical maestros through the process than the award-winning songstress than Katy? But, now that she’s leaving, someone new is surely set to take the Dark Horse si…