I don't think you can buy ruffed grouse. You can buy hungarian or chukar partridge.
My father knows about these things (big bird hunter) and ruffed grouse don't live it captivity at all. Missouri has tried a reintroduction program with limited success, but that's all trap and transfer because ruffies are far too fragile to raise in captivity.
Part of what makes 'em special, I guess.
Yes you can buy Ruffed Grouse....send me a PM and I can give you the contacts of a breeder I know. And also they are probably about the same as any other gamebird as far as keeping them in captivity according to the breeder. They actually tame down too.