Wazzup
(pass the bong)
Anyway, I'm using similar ferts and my soil mix is equal parts pearlite, vermiculite, sphagnum moss, and compost. Go to home depot and get an equal sized bag of each. I also have some of those poly water beads in it too for water retention should I ever be out for a week or 2. It is working out really well, I recommend it.
As far as what you've read in the grow guide, do not take it as gospel. From what I understand they are in the process of updating it. Look around at other posts, a lot of the experienced soil growers are using much more pearlite and vermiculite than you proposed. I'm thinking if they make up 50% of your mix, you would be in good shape. From there, add the moss for water retention and the compost for micronutrients. You're set!
Why grow in topsoil (ie dirt) if there are better mediums out there? With a 4 part mix you are gettting ideal water retention, lots of O2, all the micronutes, and its really light and airy for the roots to go nuts expanding. Its not like making a mix like this is mad expensive. A bag of pearlite goes for like $2.99. The other 3 components should be within 50 cents of that.
Food for thought anyway.
Peace,
Born420