Why would you need a 1000W power supply? I think you should spend less on the PSU and get a lower wattage unit and spend more on the board, get the GA-Z77X-D3H or even a UD3H.
It looks like the board you've found there is compatible with AMD and NVIDIA cards, but it won't work with two or more NVIDIA cards, whereas it will work with two or more AMD cards, but it will work fine with a single NVIDIA card.
It looks like the board you've found there is compatible with AMD and NVIDIA cards, but it won't work with two or more NVIDIA cards, whereas it will work with two or more AMD cards, but it will work fine with a single NVIDIA card.