I have attached photos to bases where the photo surface has become the base. I just apply a contact cement to the back of the print and the base. Then attach. I have also used a photo, mounted to foamcore as the back of a base. Just mount the photo to the foamcore the same way, and then use white glue to glue the foamcore to the back edge of the base. To suspend models above the base I use a piece or two of clear acrylic rod. You can buy acrylic rod up to about 1/4 inch diameter at many hobby shops. For larger rod you need to order it from a plastics supplier- many have online ordering.
BTW, I use Google Earth to get photos of airbases and such. In many cases the model is a period model and the bases have been greatly changed since the era of the model, but I just hope folks don't mind. As long as it looks like an airport or an airbase.