I built my workstation with and AMD 8350 and have had it overclocked at 4.2 ghz at times and my current Hyper 212 EVO handles it well almost all the time with no problems and works great for me. My problem is that current case is the cheapest thing I could find and I happened to get a 4u server chassis for free. With moving my system I have found that my current cooler is too tall to fit. The chassis has extreme front to back airflow so it would work best with a tower cooler that doesn't have a fan or can easily be taken off. I'm currently a college student so the cheaper the better as long as it can last. Thanks for any help!
Not the most silent solution but from the numbers I found, this should work. Dynatron Cooler 150mm high
The Thermaltake Frio Silent is a little smaller with the same cooling performance.
If you need to get as small as possible hight-wise get the BigTyp Revo