At work, we use these units http://www.nexsan.com/products/products/ataboy2/ataboy2.html
as well as
http://www.nexsan.com/products/products/atabeast/atabeast.html
They both use ATA drives with a dedicated ATA controller PER DRIVE, so performance is pretty darned good.
Admittedly this may be more than your average home user would need, but these things are already in use for video archives.
_________________________
========================== the chewtoy for the dog of Life