Train Horns? Need suggestions.

[PARAGON]

The Viair is the only option of those two but follow Dan's advice. The Viair's compressor is a 100% duty compressor so you don't have to worry about it running all the time and wearing out if you set up the air as on-board air for tires, tools, etc.

You'll have a much easier time trying to fit a tank of that size somewhere. I have 5 gallon tank and it will not fit anywhere within reason.

Buy the components separate and find a tank with at least one 1/2" port.