Train Horns 101 Please I want to hear it all

[skipnay]

Looking into getting a set of Horns. I like the K3LA's!!! Is it worth the money to buy the expensive ones or just cheap train horns? I actually have 2 five gallon tanks as of right now off of offroad trucks. Just need to put them on my truck. Would also like to use my air for air bags and inflate tires to toys like ATV's and such... So what would you go with?

Here is what I was thinking for parts:

Dual Pewter Viair 480C Air Compressor Kit (480)
Constant Duty, 200 PSI, 100% Duty, 3.53 CFM
Low Price: $379.95

or

Air Zenith OB2 Air Compressor
Constant Duty, 200 PSI, 100% Duty, 3.8 CFM
Low Price: $349.99

Plus I will probably go with bigger air lines. The bigger the better right? Give me your 101. Pro's and con's of your system and what you would and wouldn't change if you had to do it all over again...