If you don't plan on overclocking then the stock cooler should be fine. If you want to upgrade to have your CPU run cooler than I would recommend the Cooler Master Hyper 212, its under $30 and is a great cooler for that price. You have a powerful CPU and you don't really need to overclock.
Which cooler are you using? Also is it overclocked? If you are running the stock cooler than those temperatures look about right. In general I would suggest staying under 80C.
If you don't plan on overclocking then the stock cooler should be fine. If you want to upgrade to have your CPU run cooler than I would recommend the Cooler Master Hyper 212, its under $30 and is a great cooler for that price. You have a powerful CPU and you don't really need to overclock.