Get your friend to go to one of the local bonsai nurseries to see their stock and to have a chat to the staff.
I can personally recommend two places :
1. Bonsai Northside located
http://www.bonsainorthsidenursery.com.au/
Tess or Selby will be very helpful in assisting your friend to obtain reasonably priced starter stock and all associated needs - soils tools etc.
Also visit Steve at 2. Australian Bonsai Grower located at :190 Hubner Rd, PARK RIDGE, QLD, 4125, (07) 3803 3060 (no website sorry)
These nurseries are on the opposite sides of Brisbane and so would be hard to do them both in a day, but either would have good starter stock to begin with.
If i
had to choose for a newbie, i recommend the trip to Northside and phone ahead to make sure that Tess will be there. If she's got time, she'll help your friend get off to a good start. They are both a commercial venture and so need to sell their trees to keep in the business, but there are so few places in Brisbane, i try to support them as much as the wallet can allow. Neither are there to make heaps of money and MAJORLY better than looking at the big green or blue sheds ARHH
My personal preference would be figs, but don't forget swamp cypress and grewia too and of course banksias and mels and callistemon....
Hope your friend gets off to a good start. do phone to check their hours as they close on different days.
I also highly recommend your friend take the plunge and go to a local bonsai club meeting and get some real local advice. I'm sure some other members will be able to help you with locations and meeting times etc.