You seem to be describing a software based control system. There are multiple choices at varying prices and required skill levels. Each has it's strengths. I have no knowledge of how Control4 works, so I can't make a direct comparison.
I use Elve myself for it's exceptional stability, robust capabilities, easy to program and low cost. Perhaps the software with the largest user base, but more expensive, is HomeSeer. CQC is popular, but has a steeper learning curve. Any of these are capable of doing a good job.
Basically, these are three that you should take a look at to determine which might be appealing for your application. There may be something else I have overlooked, but I'm sure someone will jump in with a suggestion.
Having open control of your own installation is wise, IMO.