rondeemc- i have nearly the identical setup you're talking about. i have a 1.1ghz tbird in a fong kai 320 from directron, with 2 75GXPs with my RAID card on the way. here's how i handled cooling and my experiences with it.
i used a 120mm alum L1A panaflo for the intake, at half volt. the fong kai has a unique shell for the intake fan that accomdates the 120mm and completely encompases it except for the pathways for air, reducing the noise a bit. i used a 92mm exhaust for the case, also at half volt. it has a CPU shroud and i have a quiet ADDA fan on the CPU (alpha pal 6035 HSF) which you cannot hear at all. i replaced the 300w PSU fan with a 80mm panaflo and that drastically cut noise down. i have a blueorb on the northbridge i disconnected the fan from because it effectively doubles the noise created by the case.
it's build solid and the fan shrouds on the intake and exhaust silence a lot of the noise, and since it is quite thick and well built with lots of room, it definitely holds in most of the noise. the antec cases are awesome, however are not quite known for their silence
