Guess maybe Ben was referring to Ray Nesci (and the family) who have the awesome bonsai nursery in Dural? I drive out from the city just to get soil, then end up buying different stock each time. Recall seeing Oak of some sort, give them a call before you go out?
Else, I have access to an Oak, which is due for a big dump of acorns in a month or two? How young a starter are you looking for?