yo i like the idea, and i support it, i was thinkin something similar to the sam thing.. i'd use the bottom space for flowering and the top for veg.. what u should be concerned with is (1)smell and ventilation (2) escaping light.. you should get a black plastic tarp to cover them, like little "doors" that u can roll up.. this way u wont interfere with the growth process, its critical that the plant recieves no light during flower in the darkness period