It would occur to me to use the image of the floor plan positioned with CSS. Then your map points, maybe icon images or spans of text, could be laid over the top, using z-index.
I'm not sure where this intersects with your php, but it sounds something like associating a workstation with its location id, then placing the map point at the location id's x,y coordinates again with css.
Computer, kill Flanders... Did I hear my name? My ears are burning...
Good start. Now finish the job.