Yes it is possible to get a 'silent' fan for your CPU. There is one that I personally favor. The Thermaltake Big Typhoon. For $50, it sports a 120mm 16dba (sound) fan, and can keep a Pentium D 930 overclocked to 4.16Ghz under 50 C!!! But there are others that can be found over the internet. The most helpful site IMO is Newegg.
Most hard drive coolers are the same, a piece of aluminum with one or two fans. There is no best one, IMO, it's all personal preference. I wouldn't buy a hard drive cooler. What I would do instead, is install the hard drive directly in front of the intake fan.
I will do some reseach and find some silent CPU heatsinks for you.
EDIT:
Here's a hard drive cooler, just to give you an idea of what it looks like:
MASSCOOL HD CoolerHere's the
Thermaltake Big Typhoon.