Well, I'm a new indoor grower myself, but I'm kind of an advanced newbie. I use Fox Farm for my indoor grow, but buying a soil to use for outdoor grows could get expensive. For a good soil you're looking at about $10 a bag of 12 dry quarts. I had to buy 10 bags just to fill eight 5 gallon planters. To do a whole outside grow area, you could be looking at 50 or 100 bags depending on how much space you're using. Unless you're thinking of doing an outdoor grow in planters, I've seen that done before.
What I would do if I were you is test the soil that you have and see how hot it is (how much nutes, and what types). Then I'd add what it doesn't have. (bone meal, blood meal, a quality compost, etc...). Being that you're in Australia you might not need to add anything. The soil's fertile there from what I understand (I could be wrong).
I would definately add something that has Mycorrhiza in it though. It's a micro organism that helps with root growth, root colonization, and the roots ability to absorb everything, even water.
As far as fertilizer you should of course get something organic. And I'd try to get a variety of different ones with all the nutes, minor & major. So if they just need Nitrogen, then you'll have something that just gives them that and not much else. If you follow my meaning.
Also, try to keep the rows with all the same strain. Different strains have different needs. This will make it easier to give one strain something that none of the other plants are asking for.
Here's a chart that lists all the nutes, the first three are the major ones, the rest are the minor ones.
Also, I understand that you have some wicked nasty bugs out there. You might want to get yourself some No-Thrip screens and screen in the growing area. That's what green houses use to keep out mites & thrips & aphids. Using UV lights at night wouldn't hurt none too much either, most bugs don't like UV. Be sure to read some of the UV threads on UV on this site before you start using it around your plants. Don't want to give them a sun burn.
And you need to check your soil for bugs or worms that might eat roots and treat for them before planting anything.
You also have to make sure that the soil has the right pH (I think). It should be 6.5 to 7, you can get a cheap pH detector for soil at most nurseries & garden centers. Use Hydrated or Dolomite Lime if you need to raise it. Use Gypsum or Iron Sulphate if you need to lower it. This should be the last thing you do since the things you add to the soil can change the pH.
That's all I can think of, hope that helps.