hi. i like #3 and #4. # 3 the concept is interesting don't care for the font in the BPR. i'm curious how the building image would look as a cityscape useing the line style in #2 also if #2 were turned into a cityscape. anything done will be scaled down for web pages so keep that in mind.
i still like #3. can you try to change the shape of the building to look more like the actual boston landmarks like entry #35. retain your idea just change the shapes.