If cost per pound of meat, production time, space requirements, time/effort expended are the issues, really, going bigger isn't the best way to go. You can produce a lot more meat, in a shorter period of time, for less cost, using less space, by going smaller. Chickens and rabbits mature fast, take less space, cost less to raise, and can fill a freezer pretty quickly. With the chickens, depending on breed, you might have to wait a little longer but you'll have the eggs as a benefit and if you pick a breed that goes broody, you have self made replacement birds. During the warm months, you can free range them (chickens) or tractor them to cut down on purchased feed requirements. As for the sheep vs cow situation, jeeze... that's a tough call that only you can really make. Sheep mature to slaughter weight a lot faster than a cow. So for meat I'd think it would be cheaper and faster to do sheep.
Since you want cow milk, I guess you could get a cow in milk, with bull calf @ her side and castrate him to make him a steer for beef 18-24 months from now. You can share the milk with the steer and breed her back. Hope her next calf is another bull to make into a steer. And then just keep doing that over time...
Since you want cow milk, I guess you could get a cow in milk, with bull calf @ her side and castrate him to make him a steer for beef 18-24 months from now. You can share the milk with the steer and breed her back. Hope her next calf is another bull to make into a steer. And then just keep doing that over time...