thats a pretty small space to grow 2 plants, with pots, you won't get much room to grow, you should try to look into Lowryder, it may be the ideal plant to grow, only problem when growing two plants at a time you do have a chance of ending up with all males
I still think a computer case is just to small. But try it you might not end up with the best producted but its well worth it to try. Let us know how it goes if you try it.