When the installer asks you do you have a SCSI controller. Say yes and tell it where to find the modules (drivers). Additional IDE controllers are considered as SCSI to an OS for some strange reason.
IMO, RAID 0 or RAID 5 should be used when you need high trhoughput speeds. You don't need high throughput for OS. RAID 0 or RAID 5 should be seperatly setup for web, database, file servers, video, or sound that needs high throughput speeds. An OS needs the lowest access latency times. SCSI hard drives or solid state hard drives will give you that. RAID 0 and RAID 5 only gives you throughput.
You are better off using a single hard drive for the OS. Also you can use some space on the RAID for a swap partition.
BTW, the drivers (modules) have to be the same version as the Promise controller BIOS version.