I'd say any lower gravity (1.046 or so or less) ale that isn't highly hopped or with lots of specialty grains could work.
You don't want anything that has to mellow, like roasted grains or a heavy bitterness, or anything that needs aging.
I like all of the ideas listed- mild, blonde, hefe. I personally don't like wheat beers, but that may be your best bet- either the hefe or an American wheat. Those are supposed to be fine when drunk very young.
Anything that has more flavor, like American amber, pale ales, stouts, etc, would take longer to meld flavors and mellow- more like 4-6 weeks for those.