You're using all stock cooling now? Well, it depends on how much you want to spend, the environment in which your computer sits and if you want the benefits associated with heroic cooling methods. If your computer is located in a temp controlled area and your case has good flow metrics (sufficient airflow in and out, with a blowhole for good measure), you should be fine. If you want a level of insurance and\or want to overclock hard, you can try some of the many great aftermarket air solutions available. If noise is an important factor with a high degree of performance and flexibility, water-cooling is a good option.
It's all about how far you want to go.
