One of the things that give more attention on the Pi is the versatility to suit any hardware project: Control servo motors, lights, automation systems, etc..
Open Lighting Project tries to establish a standardization protocols to control lighting systems via software and open source hardware.
The next awesome video shows what can be achieved with this system...
The Open Lighting Architecture (a.k.a. OLA), It is a framework that supports all types of devices and architectures. This project participated in the Google Summer of Code 2012/13. Another interesting aspect is that you have an API for languages like C++ or Python.
In short, buy a hardware that suits your project and the software that we present in the following tutorial from openlighting.org and you can control any lighting system no matter how powerful is.
It's an interesting system mounted on Open Hardware certainly be cheaper of your projects and was previously only available to enterprises.