Here is an interesting map and article about the spread of the military’s surplus gear in state and local police departments. The data is grouped by county and you can filter by aircraft, armored vehicles, body armor, grenade launchers, night vision, and assault rifles. In LA County there are 3 mine-resistant vehicles … they probably work well with all the potholes around here too!
SoCalGIS.org 
Hey I love maps so I did find your page interesting. You may want to think of a better title. When you say surplus gear some people might get what you are referring too mixed up. To me surplus gear, means something that was govt. issued was discontinued and then sold at a loss or pennys on the dollar. The gear you want this map to focus on equipment that has been transfered to the civil services from current govt. stocks (ie. The Military).
Be sure to differentiate what some people might consider surplus gear (like hand cuffs, safety vests, holsters, etc.) and basically what everyone argrees is military equipment like M-4s and MRAPs.