Out of the offlines that I personally use, they do not support Mac's but you could get whatever that software is for macs that enables you to run PC programs.
I also have a lot of problems finding software to work on my computer (Panther). I have Lightwrite, which is good for channel hook-ups and that stuff, and virtual light lab which is good for color's and that kind of stuff. I don't know of any websites, but search google for it, and i'm sure you'll find it.
Click on the Visonary installer, and any Virtuoso Manuals. This is the Offline editor for the VLPS Virtuoso console. It helps to have a second monitor to put the 3d graphic display, and I expect version 5 will be coming out soon. Hope this helps