Ok, first you have to ask yourself if you want to overclock. If you do, go for a FOP38, but be prepared for the noise. Anyone not needing that much cooling performance would surely spare that noise. I bought a retail AMD 1 Ghz and it came whith what seems to be a coolermaster DP5-6H11 heat-sink. I tried to change for a chrome orb (same as golden orb), but it was worst. So if you don't want to overclock, don't spend too much time on heat-sink (yours seems to perform fine) and try to ventilate the case and/or add some Arctic Silver thermal paste.
BTW is 56 the MAX temperature (under heavy stress) light duty or idle? If it is light duty or idle, then you might want to change that heat-sink.