freezer 7 is naff for noise. The scythe ninja can actually be run passive, so noise is no major concern. It ships with a 120mm very quiet fan, for the thermalrights you would need to buy a fan for them.
The zalmans are always OK and i'll take your word on noise but the ninja is the quietest HSF's i've ever had.
I prefer the fan layout on the CM-690, you can make it mainly bottom to top which is great for cooling and it is near silent setup that way.. it suprised me a lot!
520W is more than enough for that system, overclocked or not
If you are worried the TX would probably make more sense than the VX.
One question if I may, why the 2900XT?