dstrbdone - It's a little too late now, but I actually installed something much like you have for the same reason...

HOWEVER! When I was getting ready to cut wires from the stock horn (on the wheel) A friend of mine who is involved with johnny law 24/7 told me that that is actually illegal to disconnect or replace the default horn attatched to the wheel...
atleast in Ohio. Anything extra (as far as horns or sound devices go) has to be on a seperate button. I found a nice black square button that is extremley easy to push when your right hand is on the stick, and is very well hidden so people dont go runnin' around and blarin' my chromies under the hood... I'll post a pic of my sound bling and the button.
Nelium - As far as install and price goes for mine, since it was a WOLO dual trumped, metal, triple chrome plated horn, it cost me $90 for the kit (called the Challenger EC), and I managed to hide
all my wires in between the compressor (in generally the same location), and my dash. I ran it through existing wire loom, or added my own, and everything looks clean... Pics to follow