I'm thinking about getting a C4 system and am unsure about which controller to get. To being with, I will just be doing lighting, climate, shades, and lock in the front door. I mentioned to my dealer that later on, I would like to add a door station and 4 touchscreens so that I can answer and open the front gate throughout the house. I may consider 4 zones of audio later on but this is unlikely. Which controller should I get?