ZigBee is good, but can grt annoying when you have a lot of them, and you have to think about how to make the mesh resilient (my house is a nightmare for signal propagation...). It takes frustratingly long for all of mine to switch off. A Lightwave bridge would be a way to solve that without relays, though. They provide what you need to turn the lights on and off, and you could use Pockit for larger control panels.