Whereabouts in QLD are you going? just the Gold Coast or elsewhere?

If you're talking about a public transport ticket, contact Translink but I wouldn't think you would need to book if it's busses etc that you would be catching.

Personally I would be looking at hiring a car; having to rely on public transport can make scheduling difficult, life is much easier when you can come & go as you please. If you hire a van between you all then you all have to agree on what you are doing and when. I guess that's ok if you all want to do the same thing... I would be thinking if your brother has temper issues it might be good for you to have your own transport so you can have time out from each other if you need.

PM me if I can help