Cool, you might want to do some research on soil mixtures, as actual soil is only 1 part of what most people use. I am not pretending to be an expert because i do not grow in soil, but MJ likes a more grainy loose kind of soil so people add things to dry it out and loosen it up like sand and perlite. Do a little reading before you commit to anything.
Also I would be doing you a dis-service if I didnt point out that you can make a hydro system for about $25 - $30 that would fit into your box and use 1 outlet.
