The very best part, obviously, is that there isn't any choice that will damage the bank promise!
Be sure that you receive something durable and a seat that could survive yearlong weather.
If space isn't a very major concern, then two individual beds may work too. For instance, the space underneath the beds can be the storage.
The attic is the best space in the house to function as a functional room, like a bedroom. It is often the easiest place to add onto your house.