Another consideration is how do you plan to get the air quality data the movement is based upon. If the data is from local sensors (i.e. sensors in or around the "breathing" wall display) you can wire them directly to the control unit. However, if the data is coming from sensors blocks away or aggregated from all over the city you'll probably need some sort of Internet connection (wired or wireless) or RF transceivers. In either case you could use an Arduino-based system, but there can be a significant difference between the two in some of the parts you need, how you put them together, and the programming.