I volunteer with a cat only rescue and yes black cats have the hardest time getting adopted followed by tortishells. Actually around Halloween not only will they not adopt out black cats, they also will not adopt out orange cats for the same reasons.
Personally I'd go for an adult cat, but that's just me. Hubby would rather get a kitten. (someday when we get a new cat, not sure which way we'll go, but it won't be while we have our current three).