1. Since you will not SLI, I prefer a non-reference like cooler, (not like evga, similar to reference which blows air to the back). With that, I would go for asus, its cooler is quiet and cool.
2. Since you are not considering to OC, why not go for a factory oc version. Won't hurt much. If that's the case, go for TOP version of Asus gtx 680.
3. If in case you will plan to SLI, better go for evga, since it would sandwich the cooler if you would use coolers like Asus'.