Dont waste your money on changing from one of the best fans to one of the best fans. It won't make any difference. In fact noctua (at least the a14 and a15) at high RPM, have a really annoying sound mark, where silent wings have a very pleasing one. Noise and performance levels are within margin of error.
If u wanna fix your GPU thermals without changing the case, the cheapest solution i see, is to mod your GPU with 2x120mm fans. I'll do this myself for mine, in the near future, when I'll change some hardware in the PC.
Extra static pressure won't do anything for case fans. You see, static pressure is to push the heat from hot spots. The fan needs to be very close and perpendicular to the hot spot. In this case scenario the blow from the intake and the GPU are parallel. Pushing the same amount of air with more force and speed bellow the GPU, it will make even harder for the fans of your GPU to grab some air from the intake "stream".
Last edited by Shenhua; 02-06-2019 at 05:32 AM.