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I'm not a Nikon guy, but the only thing you're missing is a way to trigger the off-camera flashes if you plan to use them both off-cam. If your camera has a pop-up flash, you can probably trigger them with that, if you set it up properly. Otherwise, you'll need a trigger system, such as Pocket Wizard or a Nikon commander. Of course, if you use one of the speedlights on the hotshoe, you can trigger the other one with that. Any of the speedlights you suggest will do that, but I rarely recommend going backward to older models if you can afford the current one. Other than this caveat, what you've suggested is a good, basic setup. You don't mention the kind of backdrop you're planning on getting, but I would suggest not spending too much on one traditional muslin, as that pretty much limits you. Instead, I might suggest a few rolls of seamless paper (white, middle gray, etc.) to give you some additional versatility until you've mastered the basics with the equipment you've already suggested.