So you're saying that your system during gaming is at 65c? thats a great temperature actually, considering that you're running on Sli config adding extra fans might lower down it further but not much.

There are other things to consider as well such as your room temperature, I mean think abt it, if your room is hot, then you're drawing in hot air as well so placing your PC in a good and airy spot will definitely help with your temps aside from adding fans..

Having said that though, it is better to invest in a good quality fan, ones that don't fail you every few months
here are some that are trustworthy in my books
BitFenix Spectre Pros - solid and good looking, performance is not bad
Cooler Master jetflo - may be slightly loud but good airflow
Cooler Master silencio - only available with their AIO unfortunately
Artic F12 - very rare nowadays
Noctua - all grades, all varieties except LED but 6 years warranty and damn good fans