Instead of carrying a traditional suitcase or duffel bag, many missionaries use trunks or foot lockers as luggage. They are made to carry heavy loads and withstand abuse. They are affordable and have many uses on the mission field for carrying equipment. You can stand or sit on them, they can hold water, keep out dirt, and clean them with a water hose. Here are links to two popular models. Conitco and Rubbermaid Action Packer