You should debadge your car cause macco doesnt take them off to paint. Also make sure you dont get the cheapest one cause they dont get inside the door panels and some of the paint jobs they offer dont lift the engine out. So you are going to be left with a two color car.
So if you really want a good paint job go to some of your local body shops and ask them how you can reduce thier price, by debagding and tapeing and removing the engine and other ways that will lower the ammount of hours that they have to spend on your car.
If you do decide to prime the car yourself you also want to prime it grey so the painter will cover all of it, other wise you might have spots of black primer in your paint job.