Silicon Image make very good controllers.
When shopping for similar PCI controllers,
I also look for management software
included at the factory.
For example, the Promise TX4310 has
a really good "Media Patrol" utility
which saves an event log of all
detected errors:
http://www.newegg.com/Product/Product.aspx?Item=N82E16816102080
You can run it interactively, in order to do a very
thorough test of each HDD; and it allows you
to toggle features like NCQ and S.M.A.R.T.
Just don't expect blazing fast RAID 0 performance,
because the PCI bus is shared among all other
PCI devices installed on that bus; and,
the entire bus tops out at 133 MB/second.
So, you're not likely to see any differences
between a RAID 0 with 4 x HDDs
and a RAID 0 with 2 x HDDs.
Assuming that each averages ~70MB/second,
it only takes 2 of such HDDs to nearly saturate
that bandwidth of 133MB/second.
There is also the issue of the controller's
overhead, which varies from one to the next.
Generally, such low-end RAID controllers
don't have much of any on-board cache either.
GOOD LUCK!
MRFS