You might want to talk to the GIS office for the county. Some counties have firebox maps available through their GIS systems (though it doesn't appear that Stafford is one of them). They might also provide a printed map for sale.
Loudoun County, for example, has a layer under Public Safety called Fire Box Areas in their GIS system. Loudoun County Mapping GIS
Thank you both for the ideas, unfortunately Stafford's GIS system doesn't have that overlay from what I can tell and they also don't seem to publish their map on their website like a lot of other counties do. I sent an email to the fire and rescue information address asking if they could send me one or post one on their website. I have my fingers crossed I at least get a reply.