Whats your budget and how may cfm is your compressor putting out? Thats total air flow from your compressor. You can spend $10.00 (Harbor Freight) to over a Grand for a paint gun , You got to have at least 13 to 17 cfm to maintain good air pressure for good paint atomization, our youll be palying catch up whit the compressor for air to keep on painting, Have you painted a car befor ? And what kind of paint are you going to use ? A single stage like a enamel , or 2 stage base clear ? I can Help you but I need a little more information from you ,Im A retired auto body tech w/35 years in the trade ,Ive done work From frame to paint work. My thing would be start on small stuff , then when you feel good about that work your way up to bigger stuff , paint supplies cost are up and doing it over gets expensive