Richard,
I had to go through the same process of finding good training software a few years ago. After quite extensive searching I found that, at the level at which I was teaching, RANT made a good intro to Radio Aids and IF Procedures. The trouble with it is that it is mouse-controlled, so after a period on RANT, I move to the joystick-controlled Jeppesen Flitepro.
Neither is perfect, but a combination of them comes pretty close.