8 fans seem exaggerated.
I think 4 fans in the following order: 1 frontal, air input mode of 120 mm, 2 in the side panel, air input mode of 80 mm, 1 on the rear side of the case, air output mode of 120 mm.
In reality 3 fans could be enough IMO, 1 frontal, air input mode and 1 on the rear side, air output mode.
Another one, air output mode, if you want but it is a surplus.