need help with decision

Hi folks.I am most concered about a feral (tom) cat that has called my place home for about four years.No, you can't get too close to him, but when he is ready to eat, he will peep in the window.That has been the cuetest thing, since I opened the front door, and he was asleep in a propagation box I had on the poarch, and when he awoke he stuck his head where he could see, and played "peep eye", and we fed him.So we have been his "meal ticket" for more than three years.We named him "tigger", and he adoped us.
For the last weak, or so he has been carring his right front paw, and our humane society will rent a "have a heart "trap, and he was easy to trap, and today the vet wants to know what to do.
(1)amputate, and nutter
(2)put him down
(3) have orthopedic surgery at UGA vet school.
I know he is at least four years, and wild, so dressing that kind of wond would be very hard.Oh!!, he was shot, and I know we have "that" kind of neighbors around. Please give me your best opinion, thanks Mike