And the problem with breeding ewes is that you have to shear them, find a ram for next year, and then the worries of lambing. Plus you have to get all of the official nonsense started. You are suddenly a sheep producer.
The problem with orphans is that a good 50% will suddenly die on you for no reason apparent to a novice shepherd. If they have not had sufficient colostrum [why were they orphans in the first place? ] they are pretty much doomed. Also can you bear to kill them when they regard you as their Mum?
Stores are expensive, but probably the best all round way to go, they are a flying flock, so you can get in and out of them quickly, and give your land chance to rid itself of all the problems that appear with long stay sheep on a small acreage. But you are still effectively buying lamb.
But in your situation just to produce a freezer full of meat, I would consider 50 meat birds, bought day old in June, raised in movable arks on grass. Feed them largely on wheat and 'straights'. You can do the whole thing yourself that way?