Crib, bassinet or play pen

Hi ladies. So i have an 18 month old daughter who still uses her crib and we are currently expecting a little boy in February. I dont know if we should buy a crib, bassinet or use the play pen we have? The baby will be sleeping in our room until he is 2-3 months. I dont want our daughter to wake up in the middle of the night if this new baby wakes up crying in the middle of the night ( we only have 2 rooms in the house and they will be sharing rooms until we buy our house in March.

Is anyone else in the same situation as me?