While the iPad has apps available to talk to the equipment that controls what you desire, I think first you need to look at the cost of that equipment, and that fact that most if not all is only sold through installing dealers. It's an understatement to say that it can get very expensive.

Running lighting control circuits should have been addressed prior to installing the existing electrical.

Distributing the overall video/TV takes a lot of planning, design, equipment, interfaces, and then pulling a lot of different wire and cable to meet those needs.

I really don't mean to sound negative about what you want to do, but it required planning before the build and a substantial budget. You can still run a more traditional system (if you haven't sheet rocked already) by running in-wall stereo speaker wiring, including in-wall volume level controls, to each room and then back to where your entertainment equipment will be - commonly referred to as "home runs".

From there, you could find consumer price range equipment to provide you with the ability to provide whole house audio.

Once again I don't mean to sound negative, and I don't know your budget, but most of these whole house control systems get into many tens of thousands of dollars.