Our niece (12) has requested a bigger cage for her two parakeets/budgies for Christmas. Would it be better to get one that is vertical, i.e., perhaps 5' or 6' high and 2'5"-3' wide, horizontal, or square? The birds are kept in her bedroom (her parents insist on that), where space is limited, so I'm tending towards a vertical cage, but I have no knowledge of what is best for parakeets. Does it absolutely have to be a "parakeet cage", or can I also get a big one designed for smaller birds, like finches? The parakeets are allowed to fly around her bedroom for three or four hours a day, but are otherwise confined to a cage that is about 14 by 26 inches (h/w).