For your budget I would recommend a pc based controller also, although I prefer
Martin LightJockey over HogPC. A good notebook pc will run $1500 or less. The
dmx hardware interface tops out at about $2k depending on # of universes and brand, and the software is typically free. Some have a programming and/or playback
wing, which could be anywhere from $200 - $1,500 each. If you go the pc route, I would seriously recommend a second
monitor, and think about making it a touch
screen.
There's only one
Mac based
platform, the name of which I always forget because I don't know anything about Macs.
Best thing about pc based control is that most of the packages allow you to download the software for free. So you can try them before you buy.