Must the 'aqiqah for a boy be two sheep of the same type, or is it permissible for them to be, for example, a ram and a goat kid?

The Sunnah is to sacrifice two equivalent sheep for a boy, though the basic Sunnah is fulfilled with one sheep. It is a confirmed Sunnah, not obligatory, and an Eid al-Adha sacrifice is sufficient for it. It is not a condition for the aqiqah to be male; a female is sufficient, even though a male is better. It is recommended that the sheep be fat, large, beautiful, and white. There is no harm if the two sheep are of different types, such as one being a goat and the other a sheep, or if one is female and the other male. However, small young goats that have not entered their second year are not sufficient.