It's easier for a beginner to grow in potting soil. If you want to use soil instead, get some foxfarm soil at your local hydro shop. Going hydro isn't a bad idea, but soil just tends to be easier. You can put rockwool in soil, in fact you're going to have to as you can remove the plant from the rockwool. What kind of hydro set up were you thinking of? Also, 1000 watts is pretty strong for such a small grow space.