If you want a quieter GTX 680 it might be worth waiting for the Gainward Phantom II model. The Gainward Phantoms were amongst the quietest GTX 560, 570 and 580 models. The Phantom II looks to be even better. There are some details here http://www.fudzilla.com/home/item/26573-gainward-officially-announces-gtx-680-phantom
Gainward no longer sell in North America, but use their alternative brand Palit in the USA and Canada. For North America there is the Palit JetStream GTX 680 which seems to be a three fan version of the Gainward Phantom II http://www.techpowerup.com/163236/Palit-Makes-GeForce-GTX-680-JetStream-Official.html
There is a review of the Palit JetStream GTX 680 here http://www.hardwareheaven.com/reviews/1461/pg19/palit-geforce-gtx-680-jetstream-edition-graphics-card-review-power-temps-noise.html
. It does not quote idle fan speeds, but as is normal with Gainward/Palit quiet models minimum fan speed is set to 30% duty cycle rather the more normal 40%. Gainward/Palit also tend to limit upper fan speeds so that load noise is less of an issue. The video on the review page seems to bear that out.