Hello!
I think poultry will be the way to go, chickens and geese would give you different eggs and meat and use ground in quite different ways. Perhaps try some bottle lambs in spring, rear them on your grass for the summer then into the freezer? I've never butchered sheep, but a guy showed me how to do roe deer a few years ago and goat was about the same but bigger. you need cph number and keeper number from defra to keep sheep or goats. Although shooting them felt like a big deal for me they had the best deaths, at home, happy with face in a bucket of food, no idea what was about to happen, no stress at all. Yes legal for own consumption. Could you shoot rabbits on neighbouring farmland? just a thought, might save you a lot of work :-)