I have two 30x18x18 cages that i keep ontop of black travel trunks, they seem small but they work perfectly for conures. i have two foot inbetween the two cages, and a bunch of perches between the two cages, at the doors, and i have a ladder between the tops of the two cages.
i house my pineapple gcc and my yellow sided gcc together because they REALLY have some birdie-romance going on, I have my normal gcc housed near them, and
the cockateils have the cage they came with which is to the left of their set up, and winston has the cage he came with. which is ontop of my normal gccs cage.