I've got the same case with a I7-860 retail, 8GB, EVGA GTX-275, Antec CP-850 ps, and 3 Seagate 500mb 7200 rpm drives (Raid 0, and a single drive), W7-64 . I too, wanted a quiet pc. The case has good sound deadening.
At idle the loudest thing is the top case fan, under load it is the fan on...