I'm about to buy a couple of sb600s for a mobile studio. I work in a proper studio that has everything but nothing wireless or on camera so I'm a bit out of date. The plan is to get two/three sb600 flashes and control them remotely using one on the camera or the built in camera flash (if more light angles are needed). I see that this flash can't be a master, like the sb800 or sb900. What would this mean for me? I'd love to get a sb900 but the budget is tight right now. Is there a way to use them all as remote without a flash on the camera? Are there any other recommendations on set-up? I shoot mostly people for advertising, with some portraits and events (weddings/conferences). I'd use them both inside and outside. What about after market flashes? Cheaper/better options? Thanks much.