You will definately have to take the chrome trim off the sides to do the mod.
I have never had luck with a fan adapter. I tried a 60-80 adapter back when I air cooled, to eliminate the screaming 60mm Delta black label. No matter which 80mm fan I tried, the lower decibals came with at least a 5 C penalty.
Noise is bothering you huh?
heh heh heh...
Let the countdown begin.
(Let me be the first to say it...welcome to water cooling
)