I know Kandyse McClure best as Anastasia Dualla on Battlestar Galactica. I've seen her in many other things and she's a great actor. It's her physical beauty and features that naturally resemble Ahsoka Tano's beauty that makes me think she'd be a natural casting choice.
Also, these artist renditions of Ahsoka- if she were a human, look a lot like Kandyse!
Or we could cast Meevers Desu!