I have to say that sopes can take a while to make not because they are particularly difficult to make but because most North-american kitchens are not equipped with the basic, and delicious, ingredients used in them.
Cabbage Kimchi will keep up to ten days. Leftover kimchi can be added to soup and stirfries. The longer kimchi has been aged the tastier the dish.
There are less complicated 'Mock' Kimchi recipes without radish and containing scallions, if you are interested..
Fresh ginger is recommended in most Asian dishes but dried is preferred for this one. For better flavour, I recommend buying whole dried pieces and grating it yourself (rather than powedered).
There is a different type of kimchi appropiate for almost every season. Many vegetables are used. Cucumber, radish and something called water kimchi and of course napa cabbage are the most popular.