The only difference between these kits are the air compressors that come with them. The air compressor determines whether a kit is great for honking the horns quickly in succession or providing other duties such as airing up tires or using small air tools.
All of these systems use the same 2 gallon air tank and Shocker XL train horns providing them all with roughly a 3-4 second honk time and the sound loudness of a locomotive!