Maybe try to hunt down revolving light/beacons, and use the guts of them? They'll probably cost about $25-$35 each.
http://www.vehiclesafetysupply.com/peterson-763-revolving-light-g-804.html?cPath=1_11_880
I'm wondering what the amperage draw might be for 3 motors and if the game could handle it. I'm guessing the drive belt configuration was a cost saving measure for the most part.