Most industrial walking foot machines are clones of the original Singer 111W. Thread should be at least size 69, either nylon or polyester, but I prefer to do most sewing with size 92 polyester. That is just a personal preference, because polyester stands up to UV rays better and is more color fast than nylon. They are both equally strong, but polyester is more expensive than nylon. The thread should be bonded which means it has a lubricant built into it to go through the machine smoother.
The needles you need are needle system 135 X 17, and you will need at least size 16 to sew with size 69 thread. Personally, I would not use less than size 18 needles for size 69 thread. I do most of my sewing with size 22 needles, because that allows me to sew up to size 138 thread without switching needles.
No one lives forever, the trick is creating something that will.