even a GTX 680 will run on a 600 watt psu . A 7870 needs 500 watts .
You wont be crossfiring or SLI with that mb so probably a 500 watt unit is all you will ever need .....and if you were planning on using a 7850 or GTX 660ti your current psu will work
But if it will work for now depends on your current graphics card . Some older card use a lot of power .
The processor ships with a cooler , it has thermal paste on it and it works perfectly well . Aftermarket coolers will let you run cooler , quieter and overclock more but they are not needed