Hmm I've made two Hefe's so far, and both of them are more cloves than banana. As it is now, I don't really love the clove, and I really want the banana esters, but maybe you're right about clove being better for pumpkin spice.
FYI, if you want cloves, try the WB-06 dry yeast sometime. I did one with it and it came out all cloves, no banana when fermented 68-71F. But WLP 380 gives you the same thing too.
Dunkelweizen is definitely a style that not a lot of folks here do, compared to other styles. I absolutely love it, personally. My recipe is very similar to Jamil Z's from the Brewing Network. His stuff is THE BOMB.