Korean cucumbers, which are available at Asian markets, look like long, thin Persian cucumbers. Pickled, they have a wonderful crunch. To fast-track the process, you can blanch and brine the cucumbers twice a day -- once in the morning and again in the evening.
Mrs. Pai recommends using small, slender Persian cucumbers -- they are less watery and have much smaller seeds. Korean hot-pepper powder is a blend of roughly ground sweet and slightly spicy red pepper. Chile de arbol is a good substitute.