i would go with system #1 bump the psu to 1000 watt tt modular so u can and a 2nd 6970 down the road . reason for #1 ati all system super fast comuincation more options but i advise against the raid if anything goes wrong its all gone and if u get the wd 64 bit cache h/d they almost as fast as a ssd on 3.0 sata and that system proply cheaper as well but in the end its all u max