Supposedly it is the reference PCB that is the problem, so any aftermarket cards with the reference PCB.
ASUS Strix should not be affected.
Define 6 has good filters yes, Phanteks, Corsair or Lian Li cases also great picks.
Installing filters on your old PC case would be a pain, and...
Depends on how much noise you want from your PC.
An EVO will probably ramp up a lot, Gelid Phantom Black is a big air cooler or a Noctua.
If you plan on playing Greenlight/Alpha games as I do yeh throwing raw horsepower @ it will do but you will also need to consider a GPU upgrade...
Also works for a 8086K