HI,
I am about to try the same thing with CentOS 5.2 and the Intel ICH5R controller. The info I found so far is on Intel website:
http://www.intel.com/support/chipset.../cs-020663.htm
dmraid might be a possibility for the needed driver:
http://people.redhat.com/~heinzm/sw/dmraid/readme
You can also search in LinuxQuestions.org for threads:
"How to boot from RAID using "dmraid""
"My first RAID - need advice"
It seems that a real hardware raid controller is more reliable than software raid with intel matrix storage.
Did you make any progress so far?