The Gobo systems looks pretty sweet, though. I don't think you would be unhappy with it.
The only question I have is: What lights do you have now? Are these going to replace something, or be added to an existing setup?
Staying in that budget, here's a few other ideas. There's the Advanced Drive Series lights which are linkable. Like the Epsilon or Cosmic. Maybe get two of those.
There's also the 'Pod series, which you can link up with a T4 or something similar. ColorPods or Active Pods would do nicely.
I've been using MonkeyShines. I have these four Rhesus monkeys, I give them each a flashlight with colored lenses. They stand in front of my rig all night waving those flashlights. It works pretty good. And they work for peanuts! Bananas too.
Good luck!