Have a look at the Zalman 7700CU
. It has gotten great reviews, and cools better than most other air coolers available. It also uses a 120mm fan, so it will be nice and quiet.
And yes, it will fit on a skt 754 CPU.
Make sure to pick up some Arctic Silver 5 to put on your CPU to allow efficient transfer of heat from the CPU to the heatsink.
for a case fan. It is pretty quiet for moving that much air. 29dBA still isnt that quiet though, but for the amount of air that it moves...