American Dark Wheat sounds a bit weird. Must be like a Dunkelweizen, but fermented with a neutral ale yeast?
I'd use 50% regular wheat malt, maybe with a pound of "dark wheat" if you can find it. The other half should be Munich, 2-Row, or a mix, with some dark crystal malts like C120 or Special B thrown in for character.
Should be a clean, creamy beer with a sick head and a nice plum/toffee character.