Basicly, it has to drain well, the PH must be in between that line 6 - 7 (again correct me if I'm wrong) it supposed to be mixed like something / something with perlite, and some other things.. I would just go, and ask for some soil with that specific PH, I did, and mine are growing fine!

You should maybe get some fluorecent tubes for your grow, the closet is very wide!