Building a large Raid6 SATA array

Hi,
I am researching the building of the above for work, and need hardware selection advice.

Sincerely

Raphael

We've had a 3ware Escalade 8506-8 in production for about 3 months now, with 4x250GB WDC SATA drives in software RAID5 mode.

Before it went live though, I ran some checks on RAID6, as well as some filesystem stuff. Benchmarks are what they are.. but I think the results are still relevant:

http://spamaps.org/raidtests.php