Finallu my mod has been finished. It took some time due the card went to RMA for coil whine.
Now there is no more buzzing sound from Pump or from coil whine.
The fans I used on radiator is Noctua F12PWM fan as push(1000 rpm) and Noctua S12A FLX as pull(1000 rpm)
The temp on first card never goes higher than 55 degree and second card never goes higher than 51 degree on both game or benchmark.
In terms of noise is very different by person. For me I am very sensitive and my PC room is very very quite at night so I can hear any buzzing sound from outside of my house or in the room.
The money I have spend on this mod is around 400 dollars total. It may be similar price for custom loop water cooling. But due to it can use on any other Geforce reference card at the moment , I am happy with perfromance , Noise and Looks.
I wanted to keep the green Geforce GTX LED. That is why I start this mod.