Well, I think I'd start by putting in a cabinet perhaps 2 or 3 ft deep along one wall, with shelves and doors. That would become my vegging area, and if there's room left, storage of supplies. The wall I'd pick would depend on where I would get fresh air and where I would exhaust. You don't need really need the MH's, and so I would use florescent lights for vegging. The rest of the room would be flowering. You need more space for flowering than you do for vegging, because the plants get bigger as the mature. depending on the room, I would prolly get 2 600W HPS for flowering. It would be nice if you had running water there and a way to pump water/nutes out to waste. You must also make sure you have an abundant source of fresh air, as well as a good way to clean and exhaust the used air.

good luck!