You dont need a dual channel card an atto ul4s will work. http://www.attotech.com/ultra4s.html
You need to use these, and not the ul3s for future pci-x g5 compatibility. (there is no price difference from atto )
Atlas IV 10k drives are not so hot - and no more noisy than raptors.
---
to install this i used an internal round scsi cable i bought directly from adaptecs online store.
You can see this in the picture.
If you install this cleanly and tie up cables correctly, this is by far the best solution.
Airflow is maintained everywhere.
Im taking power from a splitter with the dvd drive.