You could just give him Sonos. He'll love it, you'll get the credit. I mean, Sonos is built for people like this, isn't it?

There are a number of options for a basic home theater setup. There are a number of DIY control systems. If he wants to integrate Sonos into a control system than he will have to hand the keys over to you. Not because you don't want to let him do it himself, but because your hands will be tied. I'd be hesitant to put any RTI equipment in a DIY guys house. That AD4 may lead him to look into what else they have. Next thing you know he is calling looking for a T3V+ or whatever and software so he can program it.