Current Ultrashift uses 4.1 casing for the derailleurs, 4.9 casing for the brakes. The cable is 1.2 for the shifters, 1.6 for the brakes. Older campy Ergos could use just about any housing, the new shape, not so much. I honestly don't understand why someone would buy Campy Ergos and go to Walmart for cables/casing. I suppose if you are going there for cables, you may as well pick up some Bell tyres while you're there. They are prbably as good as anything else.
