Hi, I'm not sure where exactly to find those specific walking onions, and to find the sets might be difficult. However, if you just go to a seed catalogs web site like jonnys, vis, burpees, etc. just to a search, surely you can find the seeds. . Onions are easy to start from seed. Just get some good soil in any container, a 6 pack from the nursery or whatever, plants them about a quarter inch deep, and about 10 per unit. water once, keep inside until you see the first sign of germination, then keep them out so they can get sun, watering regularly. when they all come up, just seperate them and good to go!
Egyptian onions are rarely started from seed. They are topsetting onions and rarely produce seed. Sets or plants are about the only way the general public will find them. Territorial or Southern Exposure are companies that carry the sets. Major companies like Johnny's , Burpee, Baker Creek, Fedco etc don't carry them.