Question: why do you need an external radiator u already have a triple radiator at the top, the quad out the back looks ridiculous (no offence just my opinion).
I feel as though these days people get out of hand with the radiators when they are just cooling CPU and gpu... The cases now are so big with a quad radiator on top, bottom and then dual out back... The point in water cooling is efficiency but also quieter, it's not going to be quieter replacing the 1-2 fans with 16 in push-pull config..
Not only does it not render better results past a point but it takes away from the look of the rig