I've found Bonvita rice milk chocolate at a few (good) organic / health food stores in Brisbane. OH-MY-GOD you haven't had chocolate til you've had this!!! It's hands down better than anything out there -- dairy and non-dairy alike!
A few others to try, if you're not keen on Sweet Williams (I have to admit, I'm not a big fan)... Whittaker's Bittersweet Dark Block (delicious -- not bitter like most dark chocolates...) you can get at Coles and maybe Woollies in the confectionary aisle, and as Matt.Y said, Lindt 70% is dairy-free.
There's also tropical source, which make fair-trade vegan chocolate in plain, rice crisp, toasted almond, hazelnut, mint crunch and rasberry varieties. I remember they were in Coles for a while too in the health food section (stupid, I know...!). Haven't looked for a while, maybe they're still there. Tropical source get a big thumbs up from me too!
If that doesn't suffice, yep.. try cake

or even better -- cupcakes!!
http://whyveg.com/recipes/make_this.php?recipe=35