NAS is correct that the 4003EC is private label manufactured for Simplex by Cooper Wheelock. It is a customized version of their Safepath product. The message chip is different than the chip supplied in Wheelock brand units and it has a few other minor changes.
On the first question, the 4003EC is not a complete fire alarm panel. It must be used as an adjunct to a host FACP. The microphone can be used for PA type announcements if the unit is set up for that.