1. You can use a lightbar at the same time. They are actually separate devices but the Insight could be used as the input medium. If you another lightbar (Raven or others),the GPS goes to each device separately and the boxes would not be related. 2. The Insight should be easy to setup with different grains. The full color touch screen makes this easier than ever. 3. The Insight is compatible with other devices. I have been using mine with a Raven serial 450. 4. They should be rugged enough for your uses. 5. I'm not sure of your support in Australia. I was on a Farm trip to Australia during March and did not see much Ag leader equipment although I have heard about dealers. 6. The autosteer alliance with Trimble is very new and I am not familar with it