Audio Systems: Audio system, truck garage, watt speaker

Question
I have a truck shop at home and want to install a p.a.  The system will be simple. it's basic function is to send audio into the truck garage from an office mounted 2-way radio and also allow paging.  The shop is 60ft. by 130ft, with a partition at 100ft. what size amplifier do I need, can I cover each area with a 15 watt speaker, or are more needed?

Answer
That's a tough question without seeing the area but I would probably go with a larger speaker and more wattage. You may not want it to necessarily be louder, but having more "headroom" would be nice. It is certainly better to have too much than not enough.