I just put some together and we'll see what happens. I "covered" it in a glass bowel with the last of the cabbage leaves. I also used a fresh hot pepper instead of powder, but if that's not enough I'll add some cayenne as well. I love the spice!
I think the Korean powder is pimento powder, as it is not too spicy. Cayenne and paprika would be good too. But none of that is necessary so long as you have some hot peppers. I love it hot. Kyle, do try a minced habanero in there sometime, eh?
You know, you can do an Italian giardiniera (sic?), which is similar to kimchi, by adding some pepperocino, sweet red pepper, cauliflower and some herbs like oregano and rosemary to some Napa cabbage. Cabbage was born to ferment and has all the nice little lactobaccilus bacteria on the leaves.