Is there no way to get sections for outdoor aviaries? Here in Sweden when we want to get a big cage (even a cockatiel needs at least 48" in width according to our animal welfare laws, and parrot cages that size have bars too far spaced for small birds), we simply build our cages ourselves, or buy aviary sections to make a small indoor aviary out of them.
(Yes it takes up a lot of space, but that's what it takes to have BIG birds.

)
The cage my macaw lives in has no floor so I can walk around in it, but there is an extra piece of "floor" just under the cage so it is not directly on the real floor, then there is a layer of wooden chips on top of that.
Since it is in sections, I can make it both bigger and smaller if I want to.
I mean, aviculture is not very widespread in Sweden, so there must be something like that in the US or UK or wherever you live, too?