What type of air tools to purchase?

[red20]

I have always wanted to get an air compressor / tool set up. Since I have a 20' MA project on the horizon I want to get the right stuff to assist in my project. It will also help in many of my other home projects.

1.What size air compressor should I get? Gallon, HP, CFM etc.
2.What type of spray gun? I am thinking of spraying the boat myself. I have a small 10' tender I am building with my kids that I want to practice painting.
3. I also want to run an impact wrench, nail gun etc.

I am in the research phase and am trying to learn what is the best.

Thanks