the thing you talk about the noisy fan is most probably your cpu fan, try replacing an aftermarket cooler (i highly recommend scythe ninja since that is able to run in fanless mode if you dun do any OC or anything)

another thing you can try to do is get those 120mm fans...particularly CM UV Silent fans..since each fan produces bout 20dB...which is very good and generate roughly 45CFM... not to mention its cheap too