I prefer somewhat positive air pressure inside the computer case.
This should help prevent or reduce unwanted dust from being drawn in through unfiltered vents in the case.
I've found that side panel fans can help with video card cooling.
One time I tested with an 80 CFM side panel fan and the video card temperatures were much higher!
My pet peeve is hard drive cages that restrict intake cooling air from the front of the computer case.
Lian Li should develop an adjustable noise canceling device that is tuned to reduce fan noise.
Maybe a white or pink noise generator would help.
white OR pink noise - Google Shopping Search