Viair simply makes great stuff. I suggested the 300p because its large enough without being "too big".
Personally, I went with the "On board air" route, with a 400C compressor, and a 2.5 gallon reserve tank.
I can use it to fill tires with a quick coupler and air hose, or, and its primary function, uses a leveling valve designed to operate the air suspension on nearly all highway trucks and trailers to operate the helper bags in order to maintain a level ride no matter (within reason) what kind of pin weight I have.
The most expensive option to be sure, but one that is well worth it when you consider the increase in stability, never blinding others with your headlights pointed up into the sky and repairing a flat tire with a plug kit and a hose.
2008 F350 King Ranch, 6.4 full delete, studded and tuned. On board air, automatic air levelling