you were doing ok, it always gives a device busy error, you need to boot into -s then do the commands.

You cannot use hadware raid with the leopard there is no kext for hardware raid support.
only software raid is supported. Don't confuse the two.

It will work with the sata drives you just need to keep trying, boot of the cd with -s and it will let you do the commands.
I had the same problems and just worked through them.

Good Luck