In the past few years aviaries seem to be more the norm...which is really been great to see!
There are several how too books written about building aviaries as well and have been for a few years. I would guess if anyone did a search at Amazon.com for aviary that something would come up. There is also a new book out by Robert Young I haven't seen yet. I have a few of the older ones but not sure where they are at the moment.
Some mesh/wire suppliers
http://www.kwcages.com/
http://www.meshphoto.com/
http://www.valentineinc.com/
OR talk to your local farm or hardware store too. sometimes they can order what you need. If using galvanized wire just be sure that its galvanized AFTER welding. IT should say right on it..GAW.
The carport frames are fine but be sure to anchor them well and after you do you will lose some height. Other options can also be found at greenhouse suppliers. You can purchase the frame only in many cases and then add your own wire. You use fender washers and sheet metal screws.....its not that hard. The nicest doors I have found are greenhouse doors. They're light and nice and flat (not bulky) and easy to attach a latch to.
Shauna