i collected the parts over a year or so on E-bay (horns, switches, air tank, etc) and went with elec on-board. Primarily for air-mattress & camping stuff more than wheeling.
Added air-horns to the setup easily!!!! Have a switch next to the air pump switch that adds the LOUD horn to the regular horn!
Hey hear me now! /forums/images/graemlins/waytogo.gif
(what part of Wis are u in? I'm near Tomah)