Originally Posted by Sean.Crees
Any fan spinning faster than 1000rpm is too loud, and a 70mm fan spinning that slow isn't going to push enough air. Also there are tonality issues with 70mm fans.
The fans don't need to move alot of air when the system is idle. When under load they will kick up but the GPU is still louder. Aftermarket coolers are quieter but if you raise the GPU, you will loose the optical, 2.5", and 3.5" mounts. You can probably stick a 2.5" on top of the PSU. At this point there's enough room there.
What you intend with 120mm fans will take some moding. I don't think your going to get a 120mm fan anywhere in here (except above the CPU) unless you raise the GPU and use a 2-slot GPU cooler. Then you will have room for a 120mm and a drive or two.