The only thing you need to know about the fertz is the 3 numbers that appear on the label such as 24-18-19 this number tells you of the amount of each of the newtz. MG has a wide verity of potencies; I use 2 different types of MG, 1 for veg and another for flowering. I've never had problems...
I suggest using LEDS and theres no need for light rails, as they use way less electric. As for dirt get a good mix of worm castings, sand, and peril; you should have enough for a nice setup with LEDS. The LEDS cost more then HPS but , way less heat and power usage will more then pay for...