Electric off road is definately a good class to get in to. I have been doing it since i was about 8 and had to give up the sport/hobby when i went to uni. I have just decided to get back into buggies and bought a 4wd Losi. It had its first outing yesterday, it was great fun! Having been racing touring cars the chance to get a bit of air and negocite bumps was such a laugh!
Thats one of the pros of off road, but i also find the atmosphere at these meetings a bit more relaxing, we had a laugh on the rostrum and it was a really enjoyable day (until the rain came!)
As for con's it has to be the overshadowing popularity of the tourers. I'm not sure about Austrailia, but in the UK numbers are low although there are a prople coming back now.
Car wise i think it would be best to go down to your local track and have a nose around. What is the most popular class and chassis etc and go from there!
Hope some of this has been helpful