Best Simpson pressure washer for $840-$900

I'm on a fire department which was awarded a grant for a Simpson power washer. In the original application, PS60483 was used which is a 4 gpm, with crx420 engine and the reliable AAA pump. We'd use this for washing trucks, equipment/tools, and fire hose. Is there a different set up or version that would be better for us in that price range?