Well I found this place and it seems they have a nice selection.
http://www.windywillows.co.za/west-rand-johannesburg-roodepoort-honeydew-wholesale-nursery/trees/
Mostly big trees but they have a few saplings. Gonna have a look this weekend. Hope they have old/ugly or something.
@Bonsai Nut - looking for the shimpaku but I can't find anywhere. That or I am blind as a bat.
Dayham, That was quit a ride.
Completely unfamiliar with most of those genera present on this nursery's site.
Being the curious ol" ass I "right click>Google" Just spent like two hours and
--at the risk of sounding dramatic--CryMeAF'gRiver. Dude there are tons of
available species quite suitable for bonsai available to you. Some suitable enough
that I can only say Jealous. Visit and get to search about. There were actually
some of your indigenous species that made me need a bib. Beat the brush . . .
Literally.
PS: Got one in the ground myself;
too early to report.