The 430ex doesn't hook up to wireless transmitters, but do respond to infra red transmitters, so if you were to get either the 580 or 600, you'd be better off with the 580.
The 600 also won't wirelessly trigger aftermarket wireless receivers sadly, I found this out the expensive way and was not pleased.
So, if you plan to still use the 430s only, stick to the infrared only 580. And save money if there's a price difference. (Haven't looked at prices lately)