rhahn, it must have been down for a little while. That is how I found 10 results. Anyhow, I'll try to help with your first post.
1) I was wondering what the differences were among air brushes?
Single and double action. Single action is like a spray can, double action you can alter your air and paint intake for fades and stuff like that.
2) Also, what air brush do you really need to paint lures and what are the best ones to buy?
I have used a Badger 150 since college, 20 years ago. Perfect and durable. Once you get further into what you want you can get an illustrators gun or stay put with the Badger.