Through much experimentation through trial and error here's what I'm running at level 40. I dual wield for faster interrupts and more spirit generation.
It's funny how when reading the tooltips explosion of light doesn't sound like the most amazing spirit dump, but in practice I've found it to be by far the most effective (maybe most mobs have low holy resist?). I also find mystic ally to be extemely undervalued, as well as taking serenity over breath of heaven. I'll probably change up the rune on seven sided strike when I get the final one.