Gday Lachie,
It will be in your best interest to put them in the ground to grow for a while. I know all of this is new to you, and that you want instant bonsai, i know because i was [and probably still am] in the mind set that it happens over night, it doesnt
Everything your doing right now i did i at the start of this year, over looked posts, didnt take into account this a very patience intensive hobby, DIDNT USE THE SEARCH BAR/WIKI pages, and went to bunnings for stock....FAIL.
Thats why ill be straight up with you.
Tip's:
1. Someone told me GROW BIG, FINISH SMALL [didnt make sense to me until about a month ago].
Look for plants that have strong roots [nebari] a thick trunk, dense foliage, healthy branches, movement in the trunk.
The tree's you like today you wont even think twice about in a years time.
Those Bunno's bonsai starters are like a 20 yr plan, especially with slow growing shrubs.
2. Have a good look at the stuff these guys are producing. Examine every style possible, find what appeals to you come back and ask questions, dont ever hesitate to ask questions. EVER.
I'll leave it at that for now. Too much

for me let alone you.