You don't want that. Not because it's open box, but because it's not SLI capable. That's an ATI Crossfire supported board.
You will need something like this: ASUS M4N72-E AM2+/AM2 NVIDIA nForce 750a SLI
The thing with an open box motherboard is that in most cases, it doesn't have any cables or accessories. Most times it's just a bare board.