First off, you can't keep a single sheep on its own, so you will need two.
You would be better with wethers as the possibility of taint won't arise. I don't have a problem with the meat from young rams, except occasionally Shetlands which for some reason are stinkier than many other breeds, and this can come through in the meat.
Raising the primitives for meat involves keeping them until they are 16 months old. They won't put on weight over the winter no matter what grain-type feed you give them. They will need ad lib hay (one sheep eats on average 5 bales of hay over the winter, but we are halfway through now, so you would need half a dozern small square bales, or one big round bale, with some left over) then will start to grow as the grass comes in. If you leave them much later than August and they are entire, then the risk of taint grows, the closer to tupping time (Nov) you get.
If you want a big carcase then go for a big, quick finishing breed, but they will all have gone off for slaughter by now. If you don't need massive joints but want top flavour, then Shetland wethers at 16 months are perfect