Why not use a Pro-Mix BX?
It is a soilless mix. I found it a very good medium... Moreover, now they started to add Mycorise PRO into there... it is a beneficial fungus (10-0-0) and it works like a root stimulator for the first week and then you can start adding nutes. And yes, you can forget about PH with using Pro-Mix.

Sorry, if this comment was not what you wanted to hear.
It is just my 2 cents imp: GL!