im in europe so whatever i can get locally or thru amazon, ebay etc......
what is aeration? is that stuff like perlite or what?
Where in europe?..............I'm in the UK and this brought me problems following the recipe. For your compost, it is important not to buy a bag from a store, this isn't compost, rather a ready pre-mixed soil with nutrients, usually, mainly peat, a bit of compost and sometimes some aeration added, which has already been limed for ph balance. If you use that as your 1/3 compost you'll run into problems because the mix won't be right. Good compost is the most important thing in an organic grow in my opinion and the most difficult to find, if you do not make your own. I've spent hours/days/weeks looking for a good straight compost, but cannot find any, it is all pre-mixed as 'container compost' or 'multipurpose compost' etc. I even found a smaller scale composting operation supplying various organic composts, topsoils, mulches etc, they even use vermicompost in their compost mixes. But they do not sell a straight finished compost as a stand alone product.
Vermicompost is an option, but again it is down to the quality of the product you would be buying. It is becoming increasingly available online, but mainly through the bait/angling industry, so their focus is on worm production rather than producing quality castings. I've tried various online retailers at vastly varying prices, the most expensive product was by far the best, but was something like 6 times more expensive than the rest of them. Even from the same suppliers I've found that consistency of quality varies widely.
I'm sorry I've not helped much with an actual answer here, but there really is no short cut to actually acquiring a quality humus source, the only way to 'know' it's good is to make it yourself.
If you are in the UK, I may be able to point you in the right direction for some of the stuff you will need and with a little help from some of the more experienced organic growers, I'm sure we could come up with something.