I have actually read these forums for years and this is my first time posting. When I first started breeding birds over 5 years ago I read as much as I could on these forums. I no longer breed budgies, so many times I have felt that I would not register, but instead I like to read the posts and look at the photos, however... these are some of the birds I raise (I also raise African Greys, Pionus Parrots, Mini Macaws, and Amazon Parrots) and I felt that this would be a good time to join.
I actually have 3 pairs of green cheeks. They will love the aviary that you have set up for them. The nest box in there, actually, is a good box for them. I usually use a grandfather type box that is 16"-18" tall with a 12"x12" base to it.
I also wanted to let you know, that your quakers should settle down with the noise as well. I have 5 pairs, and they are very quiet now that they have settled in (and here, in Ohio, it is too cold to keep the birds outside, so all of my breeding birds live inside.)
I know I am new to this forum, but I do have quite a bit of experience in breeding these guys, so if you need anything feel free to contact me!