Hi David,
Typically, the breasts are in high demand for quick cooking (think high profit) usages such as sauteeing and grilling, which leaves the legs, carcass and giblets. In a restaurant, this is perfect because you now have almost total utilization of your materials. The carcass goes towards a garbure, a gumbo, or a consomme, the liver then becomes a mousse and finally the heart, giuzzards, and legs become confit. The confit, tucked away beneath a layer of rendered fat, now has a shelf life of a month or more.
I have made pheasant breast confit, and wouldn't do it again. You want the rich, fatty legs and thighs with tendons and connective tissue.
The fat can be reused, almost perpetually, as long as you're careful not to simmer your confit at too high a temp, in which case the fat will darken.
If you have time, it's best to cure the confit for a few days before cooking. Coarse salt, whole garlic cloves, fresh thyme twigs, bay leaf and fresh nutmeg. Rub this off before proceeding to poach. Poach until tender. You can substitute lard for some of the rendered duck fat if needed.