Generic knife guards seem to work for all knives, including Wusthof: just be sure you buy the right length for your blade. I believe I bought mine from both Bridge Kitchenware (bridgekitchenware.com) and Professional Cutlery Direct (cutlery.com).
One thing I discovered yesterday: Globals do not necessarily fit into those new translucent plastic guards that snap over the blade like a suitcase. I really like those new ones, since they won't slip off the way the old style edge guards do, but they won't work for everything. Be aware, and don't spned your money unwisely!