Plums are big in Taiwan, too. Aren't they? I think there are several nice releases from USDA in Byron and also from Auburn University that would do well in your location. I have been very interested in the AU Cherry plum, but it requires more chill than we get here. Along the same lines as plum, Ume would probably be hardy in your zone. For spices, maybe she could grow ginger, galangal, and tumeric. They would just need to be dug after the first frost and stored in the garage for planting again in spring.