Grover 1510 Stuttertone install?

ok, so looks like if I’m going to mount this under the truck, maybe the compressor/tank combo’s mounted together isnt the way to go.

I found these 3, which look like they should be better fitted for how I want to mount them. My question is does it matter what pressure switch it has? One says 90/120, the other says 200 & the third says 110/150psi.

I want the air going to the horns to be 110-115psi.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=140465140347&viewitem=&sspagename=STRK%3AMEWAX%3AIT

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=290420988267&viewitem=&sspagename=STRK%3AMEWAX%3AIT

http://www.hornblasters.com/products/details.php?i=hornair-232-horn-air-system

Here’s what the guy at hornblasters told me I would need:
1/2 airline (Distance from the tank to the valve)
1/4 to 1/2 air line fitting
1/4 valve
1/4 run tee
2 - 1/4 to 1/4 compression fittings
1/4 Air line (distance from valve to each horn)