If you are going to install solar panels then I would consider using someone that is licenced under the federal government scheme to subsidised the installation. Also they are licenced to connect a system via the power grid.
DIY is also a way to go but if not licensed then cant get funding.
I used to install panels long time ago in the outback but opted out of the industry a while back.
Placed are frequently advertised on TV. I do not endorse the folowing company but good start -
http://www.modernsolar.com.au/