I saw that these true hardware SATA RAID cards were available very  
inexpensively, and they get good reviews.  No RAID5 support, but  
RAID3 is there.

http://www.newegg.com/Product/ProductList.aspx? 
Submit=ENE&DEPA=0&Description=pny+raid&x=0&y=0

Driverless, works in Ubuntu or CentOS at least.

The company that made the chipset is gone, but firmware updates and  
other tools are archived at:

http://home19.inet.tele.dk/amigay/Soft-Port/

Thanks for thoughts!

Brian