Group multiple objects under a helper and export properties (assembly alternative)

Hi guys, I'm searching for a way to group multiple objects under single "head" object/helper. Something like assemblies but with custom properties exported in the ui panel. I want to be able to turn on and off multiple lights and do some addition stuff with one click. the idea is to turn on and off vraysun and vraydome linked together in sky system and automatically assign the hdri map to the environment slot. Please suggest what will be the best way to go. I'm fairly new to scripting and still learning the basics.