This was performed by our friends from DCC Xpress installations.
They offer high quality WOWSound installations for a flat rate complete with free return shipping!
You can find them at:

These items are available in the WDK-ATL-8 which was used for this installation.
AS-MB2 Motherboard WOW121-Diesel Decoder KA4 Keep-Alive™ UNIV-SH2-O WOWSpeaker Kit
Click here for more information on the WDK-ATL-8 and the rest of the WOWDiesel Kits line.