Here is my setup. I have a tank that I carry around and a 75' air hose.
I used my factory compressor. The main thing is trying to find a water seperator that can stand the heat of the engine compartment. My bowl cracked and really reduced the amount of air reaching the tank. The highest rated filter I have seen is rated to 175 degrees, far less than the normal engine compartment.
I plan on relocating the filter to the air tank. I used a small compressor filter for the intake.
Recently though, the air filter snapped off and the main plumbing broke at a fitting.