schuang74,
obviously you don't really care too much about the actual performance of a hsf unit, so just use the retail fan, it's free, and only 1 or 2* difference based on most tests *wink*
mikewarrior is spreading the truth, and if you don't want to hear it, then don't read it. but, if you want the best performance out of your hsf unit, then you need to realize that the method most large websites use is inaccurate, and that the built-in probe on your motherboard is basically lying to you.
also, the hedgehog is undoubtedly the best hsf, BUT, they do need some slight modification to ensure the maximum thermal dispensation. this involves lapping it (basically, just sanding it) up to 2000 grit. i suggest a 600 grit to get it smoother, then move to 1000, then 1500, then finish off with 2000... the less thermal paste you use, the better, just a SMALL dab of ArticSilver on a lapped hsf gives the best results in my experience (and higher overclocks in many cases!)