If you have a room, you don't need a box at all, unless you will be using the room for stuff that interferes with the light schedules. If you build a cabinet or box, like bud luv says, taller is better. I don't know if you have 10' ceilings, but I would make it that tall if so, or however tall your ceiling is. And if money were really not an issue, I would probably spend about 50 thousand on one room.