This is going to depend on the size of your kit and your situation. Of course, you will want something that is compact enough to tuck away but something that will accommodate all your supplies and equipment. Something that is well-organized and closes tightly to keep everything in place is important. Consider a case that is waterproof in the event you are stranded in the rain or snow. You will also want to keep out the bugs and tiny critters that could creep in unexpectedly.