I just put togethermy first home build and have got good benchmark except for one problem the fan noise produced by the phenom 965 is very loud,it sounds like a jet engine!! lol, but seriously if I install a cooler will this solve this, I used arctic silver 5, my idle temps are 46 celsius is this normal?
Yes, an aftermarket HSF should not be as loud or just replace the stock fan with a lower DbA fan.
Your temps seem a little high for stock temps unless you are looking a 89c ambient temps in your room. Based on those temps, I would recommend an HSF for that reason alone. Of course, the thermal compound may be too thick or the HSF isn't fully seated, which will all effect your CPU temps.