not every amd will work hot, same for intel cpus, opterons afik, are not popular for being hot but not cold either, as normal as other cpus, still not much common in a desktop pc
mostly the heat comes from the southbridge and the video card, on those, such big fan could be benefical but not sure how much
a metal bladed fan that big won't be silent inside that case, it will be as noisy as a psu fan and 2 small fans, the same with the same airflow, maybe a bit better thanks to the case design, or the lack of it