ideas
I think it is very cool what you are trying to do. I have some concerns about controlling the temperature during the winter. I live in rockport tx and it is cold here for more than four to six weeks. I am pretty sure you would have to heat your cage quite a bit in the winter even if you put up barriers to block the screen and try to trap the heat in. The electric bill for that would be pretty high. As far as construction is concerned I would go 4x4 s four your corner posts 2x4s for your runners and cross braces. I would use screws to tie it all together. You can buy some L brackets and brackets that are made for the corners where you have three supports coming together. I built a small walk in cage out of pvc pipe and shrimp net. It is easy to move and I could take it down and put it up if I wanted since I did not glue it together. You would also have to treat your would several times to water proof it. Just a few things that come to mind. I would show you my cage but I have hell trying to post pics. It is cheap and easy. It doesn't have the best curb appeal but it is functional. If I did it again I would use screen to keep out all the insects around here. I have to watch my cham closely. He will eat anything when he is outside.