RAID for storage but single HDD for OS?

[Dr Nick]

Hi everybody,
Would it work to have 2 Segate 120GB Ultra ATA drives in a RAID 0 configuration but use an extra 9GB i have just for the OS? How would i set this up? RAID the 2 first then instal Windows or instal first?

Also, Should i use a PCI RAID controller or just software or a combo? Which works better (faster)?

Thanks