That's essentially correct, but in my case the "brain" would be my HTPC. I store all my movies and TV shows on networked hard drives and play them using XBMC which provides a really nice interface for browsing movies, music, TV Shows, etc. If you plan to incorporate a PC into your home theater setup, you can simply plug something like
this into an open USB port. It allows the PC to "blast" IR signals out into the theater room to control lights, receiver, projecter, etc.
Taking this one step further, you would be looking for an app for the iPad which would allow it to manipulate the USB-UIRT (IR receiver/transmitter) which is plugged into the computer. A quick search indicates there are several available, including
touch control which specifically details compatibility with the USB-UIRT I linked above.
There's plenty of information online to help you set this stuff up, so you definitely shouldn't need to pay an installer, and if you're at all handy with PC's you can configure a 1080p capable HTPC for well under $500.