It will be just fine without overclocking
and as far as coolers go, the coolermaster 212 evo is one of the best around for the price and is only $30.
If you spend up to 60 on an air cooler, you'll be able to get some pretty decent overclocks on that cpu.
If you want to spend up to $100 on cooling, such as an all in one water cooler, you would be able to get slightly better overclocks and temps