For a warehouse/factory style building that wasn't too large, and too overbearing in a small layout, I chose DPM's luggage factory.  I've put the basic building together, but I still need to add smokestacks, window glazing, and the like.  Initially, especially with the lighter color, this building dominated the area.  Once the hills were created, and once the ground cover was added, the building dominated a bit less.  As the trees go in, this building should be even less dominating.

The model itself is pretty inexpensive, so I plan on buying a second one (pretty soon, in case THAT item isn't available for too long).  I will just put this one together with the basics, and leave it at that for now.  Then, in the future, once the other scenes are done, I plan on putting together the other building, except this time I will detail the interior, and light the interior and exterior of the building.