Bomb-proof touring and adventure panniers from the masters of waterproof-ness (is that a word?).
These things are virtually indestructable, and have a clever fitting/locking system that can be serviced in the middle of nowhere with minimal tools (that you'll be carrying anyway - middle of nowhere, remember!).
Roll top closure to hide you possessions from the elements. The QL 2 mounting system will fit racks up to 16mm using a set of swappable inserts.