Brooks has a minimum order requirement. Orders smaller than the required minimum have a longer lead time as we need to consolidate onto a stock order. If you need a faster lead time, simply exceed the minimum order amount.
“where signs or other means are used to indicate fire extinguisher location they shall be visible from the normal path of travel".
There are some codes around the country that say they should be 6” from the finished ceiling. Ultimately it boils down to the local authority having jurisdiction on where these need to be. I hope this information is able to help.