Ok. If the empty spots bother you, then you can build around it. Most any material would work, but with the updated pictures I just uploaded, I used quartz. These are a bit big, but would look quite nice in a large scale build. I can probably trim them up and still make them look decent at least if you think this takes up too much space. but overall, the mechanism you had was rather large and with the visible pistons, would clash on creative scales. A smaller mechanism is always preferable when it comes to machinery. Efficiency is how most redstone is rated. These mimic real life streetlights in that they hang approximately 8 meters from ground level, has no visible wiring from ground level, and can hang out over the road/street in question. The longer one has no visible wiring at all, save for the sensor on top, which you can see on most streetlights.