Hi. I lost two toes last summer. (See my blog "This little piggy" in the forum.) I don't believe there are any toe prosthetics, or that they would be particularly useful. During my recovery, I wore a special shoe for toe amputees. It is made under the name "Powerstep" and makes a very comfortable shoe. I had occasion to talk to a man wearing the same kind of shoe who had lost his big toe (I lost the second and third toe on my right foot.) Honestly, the worst thing about recovery was having to rest my foot, and getting little or no exercise. I still haven't fully recovered my strength for walking longer distances. It will take a while. I'm waiting for the warm weather to return. In the meantime, the shoes I am wearing are ordinary sneakers with a pretty ordinary orthotic. He may want to consider getting a cane, as I did, to help with the loss of strength and balance that may occur, and see if his employer can make any accommodation for what is actually a handicap. Perhaps a tall chair, if that will allow him the range of motion he needs to do his job. Where I live, employers are required to make such accommodations.
Prosthetics are made for people who have lost the front half of their foot, but we are not there yet, and with care and a little luck, we won't be. Give your friend my best wishes, and if you think I can answer anything more, let me know.